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92 GLOSSARY
Adaptation
Trait of an organism's structure, physiology, or
behavior that enables it to live in its
environment.
Alkaline
Substances that increase the number of
hydroxide ions (OH’) in a solution; having a pH
greater than 7; basic; opposite of acidic.
Amino Acid
Organic molecule containing nitrogen in the
form of ammonia (NH2°) and a carboxyl
group (COOH’) joined to the same carbon
atom. They form the building blocks of
protein molecules.
Amphibian
Group of animals that today includes frogs,
toads, salamanders, and limbless caecilians.
Ancestor
Parent, grandparent, or more remote forebear
that transmits certain genetic characteristics to
its descendants.
Antidote
Substance that neutralizes the action of a
specific poison.
Antipoisonous Serum
Specially prepared substance used to neutralize
toxins from the bite of a specific snake in
persons who show signs of poisoning.
Aorta
Main artery in blood circulation systems. It
sends blood to other tissues of the body.
Biped
Animal that stands upright, walks, or runs using
only the two hind limbs.
Carbon-14
Radioactive carbon isotope whose concentration
can help determine the age of fossils.
Carboniferous
Geological period during the Paleozoic Era,
which took place between 360 and 251 million
years ago.
Carnivore
Animal that obtains its nutrients and energy by
eating flesh.
Carrion Eater
Animal that eats the flesh of a dead animal.
Cellular Membrane
Flexible lipid envelope covering all living cells. It
contains cytoplasm and regulates the
interchange of water and gases with the
environment.
Cerebellum
A section of the brain in vertebrates located
above the brain stem and behind and below the
cerebrum. It coordinates muscular activity and
maintains balance.
Chelonia
Collective term for land and sea turtles.
Chordate
Animal that belongs to the phylum Chordata;
any animal having a spinal cord, whether
throughout its development or only in certain
stages. Animals that are not chordates are
called invertebrates.
Chromosome
Structure that carries the genes and, in
eukaryotic cells, is composed of filaments of
chromatin that contract during mitosis and
meiosis.
Class
Taxonomic group above order and below
phylum. For example, the class Reptilia, within
the phylum Chordata, contains orders such as
Squamata and suborders such as Sauria.
Cloaca
Exit chamber of the digestive tract of
reptiles and birds. In some species, it also
functions as the site of the reproductive and
excretory systems.
Cold-blooded
Organism whose body temperature is mainly
controlled by an external heat source because it
has little capacity to generate its own heat
through its metabolism.
Connective Tissue
Tissue that joins, supports, and protects the
other three types of tissues: epithelial, muscular,
and nervous. It contains a network composed of
many fibers surrounding the cells.
Coprolite
Fossilized animal excrement.
Cytoplasm
Fluid within the cell membrane.
Dental Battery
Set of teeth joined together to form a cutting
and grinding surface.
Dermis
Internal layer of skin, located under the
epidermis.
Dewlap
Fold of skin hanging below the chin and
extending to the chest in some lizards and other
tetrapods. It can be unfolded in territorial
battles to intimidate or to display certain moods.
DNA
Deoxyribonucleic acid. Double-helix shaped
molecule that contains encoded genetic
information.
Duvernoy's Glands
System possessed by some snakes for injecting
venom. They are a pair of modified salivary
glands, one on either side of the head.
Efferent
Nerve or blood vessel that flows from a central
point toward peripheral tissues or organs.
Egg
Fertilized ovule that develops into a new
individual. It usually also refers to the entire
structure that covers and protects the
fertilized ovule.
Embryo
The first stage of development of a multicellular
animal or plant.
Estivation
State of extreme lethargy or inactivity
caused by prolonged periods of drought or
excessive heat.
Evolution
Changes in the gene pool of a population caused
by processes such as mutation, natural
selection, and genetic drift.
Family
Taxonomic category lower than order and
higher than genus. The family Viperidae, for
example, groups together the vipers.
Fertilization
The joining of a female sex cell with a male sex
cell to form a diploid zygote.
Fossil
Remains of various types of ancient life-forms,
both plants and animals, in a rocky substrate.
They are found in the geological strata of the
Earth's surface.
Fossilization
Process by which a deceased organism becomes
a fossil over thousands of years.
Gastrolith
Stone found in the stomachs of certain
herbivorous dinosaurs that helped them crush
and digest food.
Gene
Unit of information in a chromosome; sequence
of nucleotides in the DNA molecule that carries
out a specific function.
Genetic Drift
Change in the frequency of alleles, the result of
random processes.
Genus
Taxonomic category that includes species.
Gills
Respiratory organs of aquatic animals. Often an
extension of fine tissues from the outer surface
of the body or, in vertebrates, from part of the
digestive tract.
Gland
Group of epithelial cells that produce
secretions, organized inside a covering
membrane to form an organ whose function is
to synthesize and excrete molecules that the
organ itself does not use.
Gonads
Glands that produce reproductive sex cells.
REPTILES AND DINOSAURS 93
Gondwana
Ancient southern supercontinent that broke up
180 million years ago to form Africa, South
America, Australia, Antarctica, and India.
Gregarious
Animal whose typical behavior, as a species, is
conducive to living in groups.
Herbivore
Animal that feeds on grass or other plants.
Inflammation
Nonspecific defensive reaction of the body to
the invasion of a foreign substance or organism,
frequently accompanied by the accumulation of
pus and an increase in the temperature of the
affected area.
Jacobson's Organ
Organ on the upper part of the palate that takes
in substances captured by a reptile's tongue and
analyzes them to determine various
characteristics of the object they come from.
Also called the vomeronasal organ.
Lability
Fragility of an organ; sensitivity to potentially
destructive agents.
Lamarck, Jean-Baptiste
French naturalist (1744-1829). He was the first
to propose a theory to explain the changes in
living beings.
Laurasia
Ancient northern supercontinent formed of North
America, Europe, and Asia, excluding India.
Lipids
Group of water-insoluble substances, including
fats, oils, waxes, steroids, glycolipids,
phospholipids, and carotenes.
94 GLOSSARY
REPTILES AND DINOSAURS 95
Mammals
Vertebrate animals whose females have
mammary glands, which secrete substances
that serve as food for their young.
Mass Extinction
Brief geological interval in which the extinction
rate is greatly increased, affecting a large
number of species and causing a considerable
reduction of biodiversity.
Metabolism
The sum of all the physical and chemical
transformations that occur within a cell or
organism.
Mimicry
A superficial similarity in shape, color, or
behavior on the part of certain organisms
(mimetics) to others (models) or to objects in
the environment for the purpose of hiding,
seeking protection, or some other benefit.
Mitosis
Nuclear cell division, in which two daughter
nuclei are formed that are identical to the
parent nucleus.
Molars
Group of teeth that crush food within the
mouth.
Molecular Clock
Marker used to estimate the evolutionary
distance between two species. It is evaluated
by comparing the gradual accumulation of
amino acids between the proteins of those
species.
Nucleic Acid
Molecule carrying the genetic information
of a cell.
Omnivore
Animal that feeds on animal and plant species
Opisthoglyph
Group of snakes with fangs located in the back
of the upper jaw and smaller teeth in front. The
fangs can be smooth or have a groove on the
surface that enables secretions to flow into the
wound they produced.
Order
Taxonomic category below class and above
suborder and family. For example, snakes and
saurian reptiles belong to the order Squamata.
Ovary
Organ that produces eggs (female sex cells).
Oviparous
Animal that reproduces by laying eggs.
Ovoviviparous
Animal that reproduces by forming eggs that
are carried, with soft shells, inside the female
until they hatch. They may hatch inside the
mother and come out as if they had been born
live or be expelled from the egg pouch, breaking
its membrane in order to hatch.
Ovum
A female haploid reproductive cell. It contains
half as many chromosomes as the parent cell.
Parasite
Organism that lives at the expense of another
and typically obtains nutrients that have already
been processed by the host.
Parthenogenesis
Form of asexual reproduction in certain species,
such as the gecko, in which the females produce
young (all or mostly females) without the
intervention of a male.
Pheromones
Chemical substances secreted by the
reproductive glands of certain animals in order
to attract individuals of the opposite sex.
Photoperiod
Relative length of night and day that enables
organisms to measure the change of seasons and
that influences their behavior and physiology.
Phylogeny
Evolutionary history of any taxonomic group.
Usually represented as a branching tree.
Piscivore
Animal that eats only fish.
Plastron
Lower part of the shell of a turtle or tortoise.
Predator
Animal that captures and eats other animals
as prey.
Protein
Macromolecule composed of one or more
chains of amino acids. They define the physical
characteristics of an organism and, when
acting as enzymes, regulate chemical reactions.
Proteroglyph
System of fangs in cobras, mambas, coral
snakes, and sea snakes; or the name referring
to the group that contains these types of
snakes. The fangs are located in the front of
the upper jaw and are hollow or have a surface
groove for carrying venom. They are relatively
short and are fixed in an extended position.
Protractile
Describes a type of reptilian tongue that can be
voluntarily hurled outward in an extremely
rapid, precise movement.
Reabsorption
Process in which substances that are filtered
or secreted by the kidneys and which are
necessary for maintaining the organism's
internal equilibrium are reincorporated into
the plasma.
Reflex
Simple action of the nervous system that
involves a sensory neuron, often one or more
interneurons, and one or more motor neurons.
Sensory Receptors
Cells, tissues, or organs that detect internal or
external stimuli.
Sexual Reproduction
Reproduction based on the fertilization of a
female sex cell by a male sex cell, resulting in
the production of descendants different from
either parent.
Shedding
Sloughing off or change of skin, a process that
happens naturally in many reptiles.
Smooth Muscle
Non-striated muscle that covers the walls of the
hollow organs and arteries and is controlled
involuntarily.
Solenoglyph
System of long, hollow fangs in some snakes or
the name of the group that refers to snakes
possessing this characteristic. The fangs are the
only teeth in the upper jaw, and they pivot so
that they lie flat along the roof of the mouth
when the mouth is closed. They inject venom
deep into the tissues of prey.
Species
Biological concept of a group of organisms that
can or do interbreed in the wild and are
reproductively isolated from other similar
groups. This biological concept should be
distinguished from the concept of a species as a
category and as a taxon.
Sperm Cell
Mature male sex cell, which is typically mobile
and smaller than the female sex cell.
Spinal Cord
Part of the central nervous system of
vertebrates, surrounded by the spinal column.
Striated Muscle
Muscle tissue with a striped appearance that
shows the arrangement of the contracting
elements. Includes the voluntary skeletal muscle
and the cardiac muscle.
Thalamus
Part of the prosencephalon of vertebrates
located behind and below the cerebrum. It is
the main connection center between the brain
stem and the upper cerebral regions.
Thermoregulation
Ability of reptiles to change their body
temperature by moving from a warm place to
a cooler one or vice versa.
Tissue
Group of identical cells that carry out a common
function.
Trophic Level
The position of a species in the food web or
food chain.
Uric Acid
Water-insoluble nitrogenated waste product;
the main component of the excrement of
reptiles and insects.
Vertebrates
Animals with a spinal column that provides a
structural axis and develops around the
notochord, completely replacing it in most
species.
Viviparous
Animal species whose females do not lay eggs
and whose young are born live.
Warm-blooded
Organism whose main heat source is internal
and is produced largely through oxidative
metabolism.
Zoonosis
Illness transmitted by animals to humans.
96 INDEX
Africa
chameleons, 46, 54-55
Nile crocodile: See Nile crocodile
red spitting cobra, 76
snake charming, 84
South America separation, 23
Stegosaurus fossils, 21
Suchomimus, 24
Age of Reptiles: See Mesozoic Era
Alberti, Friedrich August von, 10
alligator, 56, 57
American alligator, 32
Chinese alligator, 91
white alligator, 61
See also black caiman; crocodile
Allosauridae, 26
Alps: See Swiss Alps
Amazon tree boa, 72
American alligator, 32
amniotic egg, 5, 42
anaconda, reproduction, 42
anapsid, skull, 35
Andaman cobra, 76
Andes mountain range, formation, 23
Appalachian mountain range, formation, 22
Archaeopteryx (bird), 17
Archelon, 34
Archosaur, 12
Argentina
Eoraptor fossils, 12
Gigantosaurus fossils, 26, 27
Herrerasaurus fossils, 13
Argentinosaurus, 9
Argentinosaurus huinculensis, 24
Aruba, conservation program, 90
Aruba Island rattlesnake, 90
Asclepius, 83
Asia
cobras, 75, 76, 77
Kuhl's flying gecko, 52
serpent mask, 4
snake charming, 84-85
Asian cobra, 75, 76
asteroid, mass extinction hypotheses, 29
Atlantic Ocean
formation, 17
turtle capture rates, 88
Australia
aborigine beliefs, 82
marsupials, 17
rainbow snake, 82
spotted python, 70
thorny devil, 44-45
Australian Aborigine, mythology, 82
autotomic tail, 46, 52
Aztec mythology, 82
bacteria, Komodo dragon saliva, 49
Bahamas, habitat loss, 91
bait fishing, 88, 89
Bangladesh, snake charming, 85
Barosaurus, 8
bipedalism, 14
black and white cobra, 75
black caiman, 32, 60-61
black-necked cobra, 75
blind snake, 71
blood circulation: See circulatory system
boa constrictor, 33, 70, 72-73, 75
body temperature regulation, 33
See also anaconda
body temperature regulation: See
ectothermic regulation
box turtle, yellow-margined, 87
Brachiosaurus, 8, 19
Brazil, habitat loss, 90
Buddhism, snake representation, 83
Bulgardagh viper, extinction risk, 90
caiman, 57, 60
black caimans, 32, 60-61
nictitating membrane, 32
See also crocodile
Camarasaurus, 9, 18, 19
camouflage, 46
Canary Islands, lizard protection program, 91
Cape Dwarf chameleon, 91
carapace (shell), turtles, 43, 64, 65
Carboniferous period, first reptiles, 32
carnivore
Komodo dragons, 49
largest carnivorous dinosaur, 26
reptiles, 41
Carolini, Rubén, 26
Caudipteryx, 9, 24, 25
Central American river turtle, 33
Ceratosauria, 9
Chaco tortoise, 67
chameleon, 46, 54-55
extinction risk, 91
chelonian (turtle), 33
Chicxulub crater (Mexico), 28, 29
China
alligator reintroduction, 91
Caudipteryx, 24
dragon representation, 82, 83
Chinese alligator, extinction risk, 91
Chinese cobra, 76
Chinese soft-shelled turtle, 64
Christianity, symbolism, 82, 83
circulatory system, reptiles, 38
coal, formation, 16
cobra, 76-77
movement pattern, 71
snake charmers, 84-85
venom system, 75
Coleophysis, 8, 12
coloration, 30, 36, 54-55
colubrid (snake), skull, 75
common iguana, 46-47
conifer, Triassic Period, 10
conservation, 90-91
turtles, 88
See also endangered species
Cope, Edward D., 9
coral snake, 39
Corythosaurus, 9, 24, 25
Costa Rica, conservation practices, 88
Cretaceous Period
dinosaur dominance, 24
dinosaur species, 9, 24-25
extinction: See K-T extinction
fauna, 23
flora, 22
forests, 22
mass extinction: See K-T extinction
mountain formations, 22
turtles, 34
crocodile, 32, 56-57
Egyptian mythology, 82, 83
food sources, 41, 44
internal organs, 38-39
Mesozoic Era development, 12
movement, 57
Nile crocodile, 38-39, 57, 58-59
posture, 8
sea crocodile, 35
See also alligator
Dasypeltis (snake family), 78, 79
day gecko, 46
defensive claw, Plateosaurus, 14
desert snake, movement pattern, 71
Devonian Period, extinction, 28
diapsid, skull, 35
dinosaur, 6-29
extinction: See K-T extinction
fossil records, 8
posture, 8
primitive species, 12
winged dinosaurs, 11, 12
See also specific types, for example
Brachiosaurus
dragon
Asian representation, 82, 83
European mythology, 4
Dryosaurus, 8, 18
Duvernoy's gland, 75
ectothermic regulation (body temperature),
31, 33
lizards, 47
snakes, 70
Ecuador, Galapagos Islands: See Galapagos
Islands
egg, amniotic, 5, 42
egg-eating snake: See oophagous (egg-eating)
snake
egg tooth, 42
Egypt, crocodile worship, 82, 83
elapid (snake), skull, 75
embryonic membrane, Solomon Island skink,
32
emerald tree boa, 70-71
endangered species
black caiman: See black caiman
fishing, 88-89
giant tortoises, 67
habitat loss, 90-91
Komodo dragons, 48-49
marine turtles, 86-87
See also extinction
England, Megalosaurus fossils, 18
Eoraptor, 8
fossils, 12
Europe
dragon myths, 4
Stegosaurus fossils, 21
Swiss Alps: See Swiss Alps
extended posture, 8
extinction
REPTILES AND DINOSAURS 97
giant tortoise subspecies, 66
See also dinosaur; endangered species;
mass extinction
eye
geckos, 53
nictitating membrane, 32
pineal eye, 36
eyelash viper, 41
fauna
Cretaceous Period, 23
Jurassic Period, 17
Triassic Period, 10
feeding habit
caimans, 60
chameleons, 55
Komodo dragons, 49
marine iguanas, 51
Nile crocodiles, 59
snakes, 72-73, 78-79
fer-de-lance, 43, 90
fern, Triassic Period, 10
Fiji crested iguana, 90-91
fishing, species endangerment, 88-89
flight
geckos, 52
reptiles, 23
flora
Cretaceous Period, 22
Jurassic Period, 16
Triassic Period, 10
flute, snake charming, 84-85
food chain, reptile role, 40
forest, Cretaceous Period, 22
fossil
Camarasaurus, 18, 19
Dryosaurus, 18
early dinosaur, 9
Gigantosaurus carolinii, 26-27
herbivorous dinosaurs, 12
98 INDEX
REPTILES AND DINOSAURS 99
Herrerasaurus, 13
living fossil, 36
mass extinction evidence, 8
Megalosaurus, 18, 19
primitive reptile, 35
pterodactyl, 6-7
Stegosaurus, 20-21
G
Gaboon viper, 71
Galapagos Islands, 50
giant tortoise, 66-67, 87
marine iguana, 50-51
Garden of Eden, 82
gavial (crocodile), 56
See also crocodile
gecko, 46, 52-53
giant tortoise, 66-67, 87
Gigantosaurus, 9
Gigantosaurus carolinii, 26-27
Gila monster, 47
Gobi Desert, 25
golden fer-de-lance, 90
golden spitting cobra, 76
Gondwana, 8, 11
Laurasia separation, 17
Greco-Roman god, medicine, 83
green anaconda, 42
green iguana, 40
green sea turtle, 68, 87
green tree python, 62-63
greenhouse effect, Permian Period, 11
Gulf of Mexico, formation, 17
gymnosperm, Triassic Period, 10
H
habitat loss, 90-91
hawksbill turtle, 65, 68, 87
Heloderma (lizard), 47
herbivore, 40
Argentinosaurus, 24
Brachiosaurus, 18
saurischians, 9, 14
Stegosaurus, 20
Hermann's tortoise, 33, 65
Herrerasaurus, 8, 13
Hierro giant lizard, 91
hook, fishing, 89
human interaction, 80-91
fishing, 88-89
habitat loss, 90-91
snake charmers, 81, 84-85
it
Ichthyosaur, 12
iguana
body temperature regulation, 31, 47
characteristics, 30-31
common iguana, 46-47
extinction risk, 91
Fiji crested iguana, 90-91
green iguana, 40
marine iguana, 50-51
Turks and Caicos rock iguana, 91
Inca, reptile mythology, 82
India
Siva, 83
snake charming, 84-85
Stegosaurus fossils, 21
Indonesia, Komodo dragons, 45, 48-49
J
Jacobson's organ, 49, 74
Jamaica racer, 91
Japan, dragon representation, 82
Jura mountain range (Swiss Alps), 16
Jurassic Period, 16-17
Camarasaurus fossils, 18, 19
dinosaur fossils, 18, 19
dinosaur species, 8-9, 18
earth division, 17
fauna, 17
Megalosaurus, 8, 18, 19
Metryorhynchus, 35
sea crocodile, 35
species diversification, 18
Stegosaurus, 9, 20-21
K
K-T extinction, 7, 28
volcanic eruption hypothesis, 29
Kasyapa (mythical figure), 4
Kemp's ridley (marine turtle), 68
king cobra, 77
movement pattern, 71
Komodo dragon, 45, 48-49
Kuhl's flying gecko, 52
L
Laurasia, 8, 11
Gondwana separation, 17
leaf-tailed gecko, 52-53
leatherback sea turtle, 68-69, 87
leopard tortoise, 42-43
living fossil, tuataras, 36-37
lizard, 46-47
dispersion, 45
extinction risk, 91
Komodo dragon, 45, 48-49
number of species, 32
posture, 8
protection program, 91
loggerhead sea turtle, 41, 86
Lonesome George (giant tortoise), 66-67
long-line fishing, 89
M
Madagascar, chameleon, 46
marine iguana, 40, 50-51
marine turtle (sea turtle), 33, 65, 68-69
endangered species, 86-87, 88-89
loggerhead sea turtle, 41, 86
reproduction, 42
Marrakesh, snake charmer, 81
Marsh, Othniel C., 9, 20
marsupial, first, 17
mask, serpent, 4
mass extinction
Cretaceous Period, 22
K-T extinction, 7, 22, 28-29
meteorite impact hypothesis, 28
Permian Period, 11, 28
Triassic Period, 10
medicine, staff of Asclepius, 83
Medusa, 82
Megalosaurus, 8, 18, 19
Meller's chameleon, 46
Mesoamerican river turtle, 87
Mesozoic Era, 10, 18
reptile development, 12, 32
meteoritic impact hypothesis, mass
extinctions, 28
Metryorhynchus (sea crocodile), 35
Mexico
Chicxulub crater, 28, 29
Heloderma lizards, 47
Meyer, Hermann von, 14
Mongolia, Gobi Desert, 25
monocled cobra, 77
mountain
Andes mountain range, 23
Appalachian mountain range, 22
Cretaceous Period, 22, 23
Rocky Mountain range, 23
Swiss Alps, 16, 22, 23
movement pattern, snakes, 71
Mussaurus, 8, 12
N
naga rassa mask, 4
New Zealand, tuataras, 36-37
nictitating membrane (eye), 32
Nile crocodile, 38-39, 57, 58-59
See also crocodile
North America
Camarasaurus fossils, 18, 19
See also Mexico; United States of America
O
Old Testament, snake symbolism, 82
olive ridley (turtle): See Pacific ridley
omnivore, 41
Archelon, 34
scutosaurs, 34-35
oophagous (egg-eating) snake, 78-79
opisthoglyph (fang), 75
Ornithischian, 9, 17
Ornithodira, 11
oviparous reproduction, 32, 42-43
ovoviviparous reproduction, 32, 43
Owen, Sir Richard, 8, 9
P
Pacific ridley (olive ridley turtle), 87
pancake tortoise, 87
Pangea, 10, 11
Plateosaurus engelhardti, 14-15
splitting, 17
Triassic Period, 10
Panthalassa (ancient ocean), 11
panther chameleon, 55
Papua, beliefs, 4
Parasaurolophus, 9
pelvis, saurischians, 9
Permian Period
extinction, 11, 28
shield lizard, 34-35
pineal eye, tuataras, 36
Plateosaurus, 8
Plateosaurus engelhardti, 14-15
polyandry, 15
posture, types, 8
predatory behavior
Komodo dragons, 49
Nile crocodiles, 59
snakes, 72-73
prehensile tail, 54, 72
Prosauropoda, 9
proteroglyph (fang), 75
pterodactyl, fossil, 6-7
pterosaur, 11, 12
python, 62-63, 70, 72, 75
()-R
Quetzalcéatl, 82
rainbow boa, movement pattern, 71
rainbow snake, 82
rattlesnake, 74
Aruba Island rattlesnake, 90
movement pattern, 71
red spitting cobra, 76
regurgitation, egg-eating snakes, 79
Reig, Osvaldo, 13
reproduction
caiman, 60
100 INDEX
female system, 42
giant tortoise, 66
marine turtle, 69, 86, 87
Nile crocodile, 59
oviparous reproduction, 32, 42-43
ovoviviparous reproduction, 32, 43
snake, 71
tuatara, 37
viviparous reproduction, 43
reptile, 30-43
adaptability, 32, 34
Age of Reptiles: See Mesozoic Era
color, 30
endangered species, 88-89, 90-91
evolution, 32, 34
flying species, 23
food sources, 40
herbivores, 40
internal organs, 38-39
number of species, 39
reproduction, 34, 42-43
respiratory system, 39
skin, 38, 39
species diversity, 5
tongue, 33
See also specific types, for example iguana
respiratory system
reptile, 39
sea turtle, 69
rhombic egg-eating snake, 78-79
Rinkhal's spitting cobra, 75
Rocky Mountain range, formation, 23
rosy boa, 33
S
saliva, Komodo dragons, 49
salt gland, marine iguanas, 51
Sauria, 45
Saurischia (order), 9, 14
Gigantosaurus carolinii, 26-27
Sauropoda, 9, 19
Sauropodomorpha, 9, 14
scale
growth, 39
snake identification, 77
Squamata reptiles, 33
tuataras, 37
types, 5
scutosaur, 34-35
sea crocodile, 35
sea turtle: See marine turtle
seaweed, food source, 51
Sebek (Egyptian mythology), 82
semi-extended posture, 8
septicemia, Komodo dragon saliva, 49
serpent mask (Asia), 4
serpent sculpture (Aztec), 82
setae, geckos, 53
sexual dimorphism, Plateosaurus, 14
Seychelles, 66
shell (carapace), turtles, 43, 64, 65
shield lizard, 34-35
Singapore, Hock Keng temple, 83
Siva (Indian god), 83
skin, reptiles, 38, 39
skink, 46
Solomon Island skink, 32
skull
Brachiosaurus, 19
Giganotosaurus, 26
primitive reptiles, 35
snakes, 72, 74-75
tuataras, 36
snake, 5
blind snake, 71
body temperature regulation, 70
Duvernoy's gland, 75
egg eaters, 78-79
fangs, 75
internal organs, 70-71
Jacobson's organ, 49, 74
metabolism, 40
mouth, 74
number of species, 33
predatory behavior, 72-73
primitive species, 70, 75
religious representation, 82-83
skull anatomy, 74-75
swallowing of prey, 41
thermo-receptive pits, 71
venom system, 75
See also individual types, for example boa
constrictor
snake charmer, 80-81, 84-85
solenoglyph (fang), 75
Solomon Island skink, 32
South America
Amazon tree boa, 72
Andes formation, 23
formation, 23
habitat loss, 91
primitive dinosaurs, 12
spatulae, gecko toes, 53
spinal column, 12, 70
spitting cobra, 76
spotted python, 70
Squamata (order), 33
Sri Lanka, serpent mask, 4
staff of Asclepius, 83
Stegosauridae, 20-21
Stegosaurus, 9, 20-21
Suchomimus, 9, 24, 25
sucker, gecko toes, 53
Suriname, conservation practices, 88
swimming
crocodiles, 56
marine iguanas, 51
marine turtles, 69
Swiss Alps, 22, 23
Jura mountain range, 16
synapsid, 12
T
tail, 12
autotomic tail, 46, 52
fat storage, 47
lizards, 46
prehensile tail, 54
tuataras, 37
Tanzania, dinosaur fossils, 18
tectonic plate, movement, 22
Tertiary Period, 28
See also K-T extinction
Tetanura, 9
Tethys Sea, 11, 17
Therizinosaurus, 9, 25
Theropoda, 9
thorny devil, 44-45
toad, Christian symbol, 82
tortoise
Chaco tortoise, 67
endangered species, 87
giant tortoise, 66-67
Hermann's tortoise, 33, 65
leopard tortoise, 42-43
tree boa, 72-73
Trias, rock formation, 10
Triassic Period, 10-11
dinosaur types, 8
Plateosaurus engelhardti, 14-15
Triceratops, 9
tuatara, 36-37
Turkey, viper extinction, 90
Turks and Caicos rock iguana, 91
turtle, 64-65
anatomy, 33
commercial use, 89
endangered species, 87
fresh-water species, 64
great turtle, 34
marine: See marine turtle
number of species, 33
shell characteristics, 64, 65
wood turtle, 41
turtle exclusion device (TED), fishing, 88
Tyrannosaurus rex, 9
largest predator status, 27
U
United States of America
Appalachian mountain range formation, 22
dinosaur fossils, 18
Heloderma lizards, 47
Rocky Mountain range formation, 23
Stegosaurus fossils, 20
uric acid, 34
Vv
Velociraptor, 9
viper
eyelash viper, 41
habitat loss, 90
identification, 71
skin shedding, 49
viperid (Viperidae), 71, 74
viviparous reproduction, 43
volcanic eruption, mass extinction hypotheses,
29
W-Y
winged dinosaur: See pterosaur
wood turtle, 41
yellow-margined box turtle, 87
Yucatan Peninsula (Mexico), Chicxulub crater,
29
REPTILES AND DINOSAURS 101
opie!
ey
REPTILES AND
DINOSAURS
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BIRDS
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Birds
Contents
The Lives
of Birds
Page 40
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A Universe
of Birds
elcome to the world of birds. No
VV matter how you approach it, this
is a wonderful book not only for
its pictures, splendid illustrations, size,
and format but also because, as you read
it, you will discover secrets about these
inhabitants of the Earth, which,
according to the history of evolution,
came into being before humans. The text
is written in a direct, easy-to-understand
style. Most birds have a much-envied
ability that has inspired poems and all
types of experiments: they can fly. This
enables them to see the Earth from afar,
with its seas, mountains, rivers, cities,
and other features. It has been estimated
that more than 200 million birds migrate
each year, all over the planet. Many of
WHITE HERON (Fgretta alba)
A species easy to distinguish in
the proximity of rivers, lakes, and
lagoons
them fly thousands of miles, crossing
desolate deserts and windy seas to arrive
in Africa or Antarctica. Some find their
way using the sun, the moon, and the
stars; others follow their parents or use
the course of rivers or mountain chains as
references. In general, smaller birds
migrating across continents stop several
times to get food. It is surprising how fast
they travel, in spite of these stops: it has
been calculated that some small species
cover almost 2,500 miles (4,000 km) in
five or six days. Several studies have
shown that carrier pigeons and white-
headed sparrows, for example, can travel
more than 600 miles (1,000 km) per day.
Some ducks, such as the blue-winged teal,
complete their trip from Canada to
central Mexico in about 35 days, making
several stops to feed along the way.
whether hiding in trees, flying over
high mountaintops, or nesting in
Antarctica or on tall buildings.
Perhaps the reason for such amazement
is their behavior, which continues to be a
mystery to human beings, as well as the
differences among them. It is believed
that there are approximately 9,700 living
bird species in the world—more species
than in any other vertebrate group
except for fish. Once they reach
adulthood, birds' weight varies from a
RB irds never cease to amaze us,
mere 0.06 ounce (1.6 g), in the case of
hummingbirds, to as much as 330
pounds (150 kg) for African ostriches.
Even though most birds fly, there are
some—such as kiwis, rheas, and
ostriches—that run quickly on the
ground. Some birds, being perfectly
adapted to aquatic life, live in oceans,
rivers, and lakes. The shape of their feet
and bills varies according to the
environment in which they live. Some
aquatic species have bills modified to
filter small water particles, whereas
birds of prey have strong bent bills to
hold down and tear apart their prey.
What is the diet of birds based on?
Because of their great diversity and wide
distribution, their diets differ greatly. In
general, birds eat a bit of everything,
although insects are the most important
element of their diet. They eat fruit,
seeds, nectar, pollen, leaves, carrion, and
other vertebrates. Most birds lay their
eggs in nests. Worthy of mention is the
protective attitude that both males and
females have toward their young. Adult
birds care for their chicks, warn and
protect them against the danger of
predators, and guide them to safe
places where they can live and feed. We
invite you to investigate up close the
world of these fascinating beings that
are able to run, climb, swim, dive, and
cross the skies. @
The Nature of Birds
oS i
any scientists maintain that
birds descended from
dinosaurs because fossils of
dinosaur specimens with
feathers have been found.
As a group, birds have exceptional
eyesight—they have the largest eyes in
relation to the size of their bodies. In
addition, they have very light bones,
which are suitable for flight. Just like
their bills, birds' feet have also changed
in accordance with the functions and
particular needs of each species. For
instance, walking birds—like other
vertebrate groups—display a marked
BEYOND FEATHERS THE SENSES
ORIGIN DIFFERENT TYPES OF BILLS
SKELETON AND MUSCULATURE EXPOSED LEGS
INTERNAL ORGANS
tendency toward having a reduced
number of toes; ostriches, for example,
have only two. Some birds of prey,
such as eagles, have feet that are
veritable hooks.
8 THE NAT
URE OF BIRDS
BIRDS 9
Beyond Feathers
efining what a bird is brings to mind an animal
covered with feathers that has a toothless bill and
anterior extremities morphed into wings. Other
distinguishing characteristics are that they are warm-blooded and have
pneumatic bones—bones filled with air chambers instead of marrow.
Birds have very efficient circulatory and respiratory systems and great
neuromuscular and sensory coordination.
SENSES CREST
Great visual acuteness and
well-developed hearing
NOSTRILS
BILL
Originates in the
epidermis. It is hard
and resistant, with a
consistency similar
to that of horns.
Tt grows
continuously,
like nails and
feathers.
Variety and Uniformity
We can find birds in every type of environment:
aquatic,
and in tropical
aerial, and terrestrial, in polar regions
zones. Their adaptation to the
environment has been very successful. Nevertheless,
birds are one of the groups that display the fewest
differences among their members.
WINE-THROATED HUMMINGBIRD
,
WEIGHT OF THE
SMALLEST BIRD
AFRICAN
OSTRICH
WEIGHT OF
THE LARGEST
BIRD
A small bird that lives in North.
America and on the Iberian
Peninsula
PENGUIN
THE TEMPERATURE
IN ANTARCTICA
TAIL
in this area.
PENGUINS CAN ENDURE
The last vertebrae merge into the
pygostyle. The tail feathers develop
C <7 iy ,
GI, Uy
Lill eT; /
INT Uy)
hie: SY)
4 ZZ WY} Lit | CHEST
Adaptation to Flying
Some crucial anatomic and physiological 7
characteristics explain birds’ ability to fly.
Their bodies and feathers reduce friction with the COVERTS
air and improve lift. Their strong muscles, light
bones, air sacs, and closed double circulatory
system also play a role in their ability to fly.
FEATHERS WINGS O
Unique. No other living propel, maintain, and
animal has them. They guide birds during
are appealing for their flight. They have
structure, variety, and modified bones and
constant renewal. characteristic plumage.
IS THEIR BODY
TEMPERATURE.
THORAX
FLIGHT FEATHERS
ABDOMEN
The high demands of flying
are compensated by a high
metabolic rate. Birds
extract as many nutrients
from food as they can.
UNDERTAIL COVERTS TARSUS
FEET
Birds walk on their toes. In general,
they have three toes pointing
forward and one pointing backward.
Balance in movement. A
bird's internal architecture
contributes to its stability.
The location of its feet
and wings helps to —J
concentrate its
weight close to its
center of gravity.
IDENTIFICATION
There are differences in plumage and
skin that make it possible to identify
birds. The bill, because of its
variations, also helps to establish bird
groups.
eS
Eye Ring
—=—_$$—S
Postocular
Patch
| Eye Line
S>
Crown
Face with
Contrasting
Colors
SONGBIRDS
Passeriformes, or passerines, form
the most numerous group among
birds; they are characterized by a
well-developed syrinx that enables
them to emit harmonious songs and
trills and by a soft plumage of varied
colors. Because of their brain
development, it is believed that
passerines were the most recent
birds to come into existence.
AF
10 THE NATURE OF BIRDS
THREE TOES
WITH TALONS
The hand has three
extended fingers,
each of which is
equipped with a
strong curved talon.
Talons for
climbing
trees
() cy g e
he evolution of birds is a debated theme in science.
The most widespread theory states that birds descend
from theropods, dinosaurs that walked on two legs.
Fossils of dinosaur specimens with feathers have been found, but
Archaeopteryx, a primitive bird that lived 150 million years ago, is the
oldest relative known. Completely covered with feathers, it had a pair of
wings that enabled it to fly. However, it retained many dinosaur traits.
Its wrist joint was
more flexible than that
of modern birds, a trait
it shared with
dinosaurs.
Archaeopteryx ———
litho bette of JAWBONES WITH SPINE
ee Order Sa rischi TEETH Unlike modern Movable. The cervical
lived in the Jurassic Period, eee birds, it did not have a vertebrae have a concave
150 million years ago. Suborder Theropods horn bill. There was a joint like that of the theropods,
Diet Carnivore tight row of sharp teeth nota saddle-shaped one like
: on each jawbone. that of birds.
¥ Comparison Length 10 inches (25 cm)
: to a Human
Height 8 to 12 inches (20-30 cm)
Weight 18 ounces (500 g)
From Reptile to Bird
FURCULA
SKULL (Merged
Similar to that of Collarbone)
present-day reptiles Shaped like a
and early theropods. boomerang,
The arrangement of as in many SAURIAN PELVIS
the brain and ears theropods Hip and femur of the VERTEBRATE TAIL
reveals that it had a archosaurian, not Composed of 21 or 22 pieces.
great sense of avian, type Modern birds have tail vertebrae
THEROPODAN REPTILE PIGEON orientation and that that are fused together into a
From the Triassic Period From the Jurassic Period Alive Today it was able to UNMERGED single bone called the pygostyle.
perform complicated RIBS 23 METATARSUS
maneuvers. ee Presence of ribs in In modern birds,
the abdomen the tarsus and
(gastralia), typical of metatarsus are
i reptiles and fused into the
Fossils dinosaurs tarsometatarsus.
Several fossil samples
were found between
1861 and 1993. The first
one, found in Bavaria,
During flight, it
functioned as a
rudder. On the
: ground, it
Germany, was very provided balance
important because its for walking
discovery coincided
with the publication of
On the Origin of Species
by Charles Darwin, at a
time when the search
TOES
The foot is functionally tridactyl. Its
first toe (hallux), which usually points
FROM ARMS
for evolutionary “missing TO WINGS Tts movements backward and typically does not touch
links” fascinated It had a greater range of were limited by its Birds have the ground, is opposable, like that of
scientists. The original is motion in the upper limbs shoulder joint, which greater mobility modern birds (it can move in a direction
located in the British than primitive dinosaurs. was placed forward. than Archaeopteryx perpendicular to toes II, III, and IV).
Museum. Another fossil,
which includes the head, is in ARCHAEOPTERYX . VELOCIRAPTOR PIGEON ARCHAEOPTERYX LITHOGRAPHICA
the Berlin Museum. 150 million years ago 99 to 65 million years ago modern Graphic Reconstruction
BIRDS 13
12 THE NATURE OF BIRDS
CARPOMETACARPUS
It is formed by the
fusion of the hand
bones.
CERVICAL VERTEBRAE
Their number varies according to the
type of bird. They make the neck flexible.
Skeleton and Musculature
oth lightweight and resistant, the skeleton of birds underwent important
changes in order to adapt to flight. Some bones, like those of the skull and
wings, fused to become lighter. Birds have fewer bones than other vertebrates.
Because their bones are hollow, containing internal air chambers, the total weight of
their bones is less than that of their feathers. Birds' spines tend to be very flexible in
the cervical region and rigid near the rib cage, where a large, curved frontal bone
called the sternum attaches. The sternum features a large keel, to which the pectoral
muscles attach. These large, strong muscles are used for flapping the wings. In contrast,
running birds, such as ostriches, have more developed muscles in their legs.
CORACOIDS
MERUS
RADIUS
CARPAL
BONES
ULNA
4A
jy
Ve
a
Flapping Wings dj SKULL
a KULL
Pp 9g 9g —_—- i Light because of the
Flying demands an enormous amount of energy and fusing of bones, the skull
strength. Consequently, the muscles responsible for does not have teeth, a bony
flapping the wings become very large, easily comprising jaw, or grinding muscles.
15 percent of the weight of a flying bird. Two pairs of
pectorals, in which one muscle of the pair is bigger than UPPER LOWER
the other, work to raise and lower the wings. They HUMMINGBIRD MANDIBLE OF BILL MANDIBLE OF BILL
function symmetrically and in opposition to each other: Because of its adaptation to In some species, it is It is flexible, allowing
when one contracts, the other relaxes. Their placement stationary flight, its pectoral flexible s bidcte open their
within the thoracic cavity corresponds roughly to the muscles can account for 40 i mouths: wide
bird's center of gravity. The motion of the wings also percent of its total weight.
requires strong tendons.
DOWNWARD FLAP
Right Wing Tendon Left Wing
Humerus 7
LZ
Z ES 2
i. GZ Sa | / SS S e
The larger = oS The descending
pectorals flapping of the
contract. wings takes
The place.
Keel Pm : smaller
pectorals
relax.
IF
The pectoral
muscles
relax.
The smaller
pectorals
contract and
draw the wings
inward.
FURCULA (COLLARBONE)
Known as the wishbone, it
is unique to birds and
results from the fusion of
the collarbones.
KNEE
STERNUM
Hyperdeveloped in flying birds,
the sternum's long keel facilitates
the attachment of
the pectorals.
FEMUR
Wings
Without a doubt, wings are the greatest adaptation of birds.
Strong tendons travel through the wings and merge into the
hand bones, where the feathers are attached.
PELVIS
Biceps Extensor
oo PYGOSTYLE
The tail vertebrae
= @ are merged; the
~~ = tail feathers are .
anchored to the Pneumatic
tail.
Bones
Many of a bird's
bones are
TARSOMETATARSUS pneumatic—that is, they are
aoe aah full of air instead of bone
marrow. Some bones even
Pe See have prolongations of air
meee = pe Wane bacteaea ~_ sacs. The bones may look
TOES : — c_ ' ZA >» fragile at first glance, but
Tendons iE WY ZN it assumes a crouching é fae incre’ Tae strength
that tie the y/ : = position with its legs —— A\ 9
muscles to Iliotibialis —Y~— 7 ed bent. This causes the comes from a network
Triceps Flexor Digitorum the wing FEET Lateralis -_Le fede IRE foak to of internal
Superficialis Birds have four toes, tighten, which pulls its trabeculae
SYMN EG at AR, Manat LIES just like their ancestors, toes closed and locks its (spongy bone
. THE COLOR OF THE FLESH» the reptiles. feroneus \ ____ feet in place. This J structures),
depends on the blood circulation Longus —A\ Gastrocnemius tendon-locking (( \ which resemble
in the muscles: the more circulation, }\ mechanism keeps birds | the trusses of a
the redder the flesh. Flying birds J y from falling off branches | gcKeg metal bridge.
have red flesh, whereas nonflying birds, SUPPORT while they sleep. Toes Tendons
such as chickens, have white flesh. POSITION
14 THE NATURE OF BIRDS BIRDS 15
Internal Organs
TONGUE Respiratory System
Usually short, narrow,
triangular, and not very I) Birds have the most efficient respiratory system of any vertebrate
(Lf because of the great effort that flying demands. It has two small, almost
muscular.
; ; H ie H rigid lungs that are assisted by nine air sacs distributed throughout the body.
irds In flight can consume oxygen at a rate that a well trained athlete ESOPHAGUS The air sacs work as bellows, but they do not carry out gas exchange. Oxygen
would not be able to withstand for even a few minutes. Because of enters the bloodstream through the parabronchi, which are much like the alveoli
this oxygen consumption, all their organs have had to adapt. The oe Sie tbalaed e ae pest ana ae air
lungs of birds, though smaller than those of mammals of similar size, are LUNG flows in one direction through the lungs, and blood in the lung capillaries flows
Ai H H H SYRINX Almost rigid in the opposite direction, birds can make use of all the air they inhale, much like
much more efficient. Their lungs have several air sacs that both increase biden oe Pere ae EEE TRE Eh carat.
the efficiency of their respiratory systems and make them lighter. A possible for its structure
special feature of the digestive system is a crop in the esophagus, binds tp sang) THE AIR SACS
CROP
where food is stored for digestion or for feeding the young. A bird's
heart can be four times larger in relation to its body size than a
human's in relation to its body size. e
Lung Abdominal Air Sac.«
= 6 @
Cervical Air Sac
Interclavicular
Air Sac
SECTION OF Posterior
Digestive System STOMACH bb sau Thoracic Air Sac
e reticulum
FF) Birds have no teeth. They therefore ingest food without chewing, LIVER formed by the Anterior
Le and their stomachs break it down. The stomach is divided into two parabronchi Thoracic Air Sac
GIZZARD =
facilitates the
exchange of gases
with the blood.
parts: the glandular (or proventriculus) part, which secretes acids, and
the muscular (or gizzard) part, whose muscular walls grind up what is
eaten. In general, the process is very fast because flying requires a lot of
energy, and the bird has to replenish that energy quickly. The digestive PANCREAS
system ends at the cloaca, which is an excretory orifice shared with the
20%,
SMALL
urinary system. Birds absorb almost all the water they drink.
INTESTINE
FOOD ITINERARY Esophagus STERNUM € Ai »> Ai
ir ir
STORAGE HEART
Some birds have a crop, which Anterior air Empty
enables them to store food ( Crop sacs with anterior air
and digest it later. This way 1 inhaled air 2 sacs
they decrease their exposure : Posterior air . Em
pty
to predators. ; A HUMMINGBIRD'S HEART BEATS INHALATION sacs with EXHALATION posterior
Proventriculus The eos fill new air biel fill up ail’sacs
by up with air. with air.
PRODUCTION times
The proventriculus secretes Gizzard ‘
the gastric juices that initiate a minute.
digestion. CLOACA
Rufous Hummingbird Right Jugular | { Left Superior A Highly Complex Heart
BREAKDOWN ‘Selasphorus rufus, Vena Cava ne ‘ P :
In the gizzard, a strong and ( Lf fus) Right Carotid | IR Similar to that of reptiles, but having a heart with four
muscular pouch, food is ; , a chambers instead of three, the circulatory system distributes
broken down with the help a wri — (_, nutrients and oxygen throughout the body according to the body's
of siNeriaaei eel F Pancreas : y needs. The heart's size and rate vary, depending on the bird's
sand. The stones and san ow A = ight and activities. I |, bigger birds h ller and
play the role of teeth. : < weight and activities. In general, bigger birds have smaller an
WATER ABSORPTION
occurs in the small intestine.
Birds normally get water
from the food they ingest.
EXCRETION
The cloaca expels feces mixed
with urine coming from the
excretory system.
TYPES OF GIZZARD
Granivorous Birds
3 he S ‘4
have thick muscle QW ee Carnivorous Birds =I
walls and strong fe — have thin muscle =
mucous membranes Pama
(or internal skin) to —
break down seeds.
\ Small Intestine
Intestinal
Ceca
Oviduct
=
walls because
digestion takes place
in the proventriculus.
Right \
Atrium
Right
Ventricle
Left
Atrium
Left
Ventricle
Aorta
slower hearts. For example, the heart of a seagull on the ground
beats 130 times a minute; in flight, it beats 625 times a minute. A
hummingbird's heart can beat 700 times a minute.
THE HEART'S ASYMMETRY
The left side of the heart is more developed, because it pumps blood
to the whole body. The right side pumps blood only to the lungs.
The Blood » Relaxed _ Contracted
enters through Ventricles Ventricles
the right and left They open the The blood enters the
arteries. atrioventricular valves. bloodstream.
16 THE NATURE OF BIRDS
BIRDS 17
The muscles around the eye change its shape,
alter the lens, and create greater visual
acuity: birds typically have a 20-fold
magnification (and sometimes, as in the case
of some diving birds, a 60-fold
magnification), in comparison with humans.
Their sensitivity to light is also remarkable,
with some species being able to recognize
light spectra invisible to the human eye.
Vision
[Fis the most developed sense in birds
e e | I S e S [Lei because some flight maneuvers, as
well as the recognition of food from afar,
depend on it. Birds have relatively large eyes.
n birds, the sense organs are concentrated Eee gee. they a= el ean they are
deep because the lens and the cornea—
on the head, except for the sense of witty $ supported bye i el slope
i i ony plates—project beyond the eye socket.
Bir ee A tah ai en Seats Tn hunting birds, the eyes are almost tubular.
l Vi i yes WI . —
the size of their bodies. This enables them to ee ;
see distant objects with considerable precision. : SSA, SS a SCLERA
Their field of vision is very broad, over 300 7 : —-— OF aamnocutan.-~ CHOROID
degrees, but in general they have little binocular ¥ — » MUSCLES
vision. The ear—a simple orifice, but very refined in < SS ee ris
nocturnal hunters—helps them notice sounds a FOVEA
inaudible to humans, which facilitates the detection = ss CORNEA
of prey while flying. The senses of touch and smell, a Ror — PUPIL
on the other hand, are important only to some birds, \ PN - IRIS
and the sense of taste is almost nonexistent. @ ¢ PECTEN
E — SCLEROTIC RING
TheEar eee eS ee
is ae 2 visual Field of he) **e,
Fi Birds’ ears are simpler than those of y =. FIELD OF VISION se = THE HUMAN FIELD
Le mammals: a bird's ear has no outer A Z ] a OF VISION
portion, and in some cases it is covered y / / \ " The eyes—when located on the
with rigid feathers. A notable part of 4 \ me Pi Sidgamegee ond, ais the-case 3 The eyes, located at the front, ¢
the ear is the columella—a bone that 7 =< with most birds—create a broad sooth move together, covering the (*
birds share with reptiles. The ear is field of vision: more than 300 ae Te 0 ne RR |
nonetheless well developed, and birds degrees. Each eye covers different aoe beings cannot move their eyes
have very acute hearing; whereas areas, focusing on the same object o independently from each other,
human beings can detect just one , € only when looking ahead through : they have only binocular vision.
note, birds can detect many. The ear is <® a narrow binocular field of vision.
essential to a bird's balance, a key s “ ~
factor in flying. It is also believed that ™~
in certain species the ear works as a
barometer, indicating altitude. COMPARISON OF BINOCULAR FIELDS OF VISION
UPPER TWER ~~ Binocular vision is essential for measuring allow the brain to create a third one in depth,
AUDITORY —— AUDITORY ~ distances without making mistakes. The brain or in three dimensions. Hunting birds, for which
Located at different heights on
the head, the ears cause the
sense of hearing to occur witha
slight delay. In nocturnal hunters,
such as owls, this asymmetry
allows for the triangulation of
sounds and the tracking of prey
with a minimal margin of error.
CAVITY, << caVITY
> \
Touch, Taste, and Smell
4 The sense of touch is well developed in the bill and
(Le _tongue of many birds, especially in those birds that
use them to find food, such as shore birds and
woodpeckers. Usually the tongue is narrow, with few
taste buds, but they are sufficient to distinguish
among salty, sweet, bitter, and acidic tastes. The
sense of smell is not very developed: although the
cavity is broad, the olfactory epithelium is
reduced. In some birds, such as kiwis and
scavengers (condors, for example), the
olfactory epithelium is more developed.
» processes the images that each eye generates
“separately as if they were a single
small differences between the two images
BINOCULAR
‘FIELD OF
OF VISION
image. The
HUNTING BIRDS'
FIELD OF VISION
Frontal eyes reduce the total
field of vision but allow for a
wide field of binocular vision.
MONOCULAR FIELD
the correct perception of distance is a life-and-
death matter, tend to have eyes located toward
the front, with a wide field of binocular vision.
BINOCULAR
FIELD OF
VISION
MONOCULAR
FIELD OF VISION
EXTRAOCULAR
MUSCLES
In contrast, birds with lateral eyes calculate
distance by moving their heads, but they
record a larger total field of visionto avoid
becoming prey. Owls are thé,birds
greatest binocular vision—up\to 70
\
ith thes.
reo
NONHUNTING BIRDS'
FIELD OF VISION
The lateral eyes open the field
of vision to as much as 360
degrees but reduce the
binocular field.
\
.
18 THE NATURE OF BIRDS
Different
Types of Bills
nails—that grows
down. In the ce
UPPER JAW
LOWER JAW
PREMAXILLA
LOWER
MAXILLARY
BONE
Heterogeneous Shapes
> Bills have a wide array of names and shapes,
but they are usually classified according to
their length in relation to the head (short or long);
to the curvature of its axis (pointing upward or
downward); to its width; to its general shape
(conical, stiletto-shaped, or spatula-shaped); and to
the presence or absence of accessory pieces, such
as grooves, horny plates, or false serrated teeth.
The heron fishes in shallow
COMPOSITION
AND STRUCTURE
The jaws are covered with a hard
horn layer called the ramphotheca,
which is the external, visible
portion. This determines the
‘Vey bill's color.
~
BIRDS 19
Parts of the Bill
| Each jaw has characteristic elements. In the
of upper one, from the back to the front, are the
nostrils (or nasal cavities), the culmen (or maxillary
cover), and the tip, which, in carnivorous birds,
contains the tomial, or killing, tooth. In the lower
jaw is the gonys, or cover. The variations found in
each part of the bill are conditioned by the bill's
function.
DENTARY
With their long, thick bills,
they can reach fruit located
on branches that are too
thin for the bird to sit on.
Their bills are also used to
break the peels and seeds
of fruits.
Like granivores in general,
CULMEN
Hardness
Its long, stout bill is
extraordinarily hard. Despite
its appearance, the bill is
very light, and birds can use
it adeptly to seize and to
open the fruits they eat.
TIP
Flamingos have
thin, threadlike structures
inside their bills whose
function is similar to that
of the baleen of whales.
They feed on
microorganisms through
filtration.
Tt uses the false (tomial)
waters and has a long, solid, it has a strong, conical bill, tooth at the tip to detach
— that forms a web
and increases the surface
of the foot that is in
contact with the water.
4
THE FOOT I
Claws, Scales, and Spurs
These striking foot structures play a role in finding food, movement,
protection, and defense, among other things. The claws can be long
and sharp, in the case of birds of prey, or short and round, in the case of
rd walking birds. Owls have a comblike claw that they use to groom their
plumage. Their scales, inherited from reptiles, help protect their
feet. In some cases, they help the birds to move through
water. Many birds, such as chickens, pheasants, and
crested screamers (a South American waterbird), 4
Y
f
have a spur, which they use as a
defensive or offensive : A
weapon.
BALD EAGLE
(Talons)
Very long, curved,
pointed claws. They
envelop the body of
the prey and
pierce it.
FEET DESIGNED \ \
FOR CLIMBING
Found on parrots, “
woodpeckers, and
cuckoos. The hallux
and the fourth toe
are pointed
backward. This
arrangement TIBIA
provides the The tibia merges
birds with more strength into tarsal bones and
for climbing tree trunks. forms the tibiotarsus.
Tt has a slightly
FEET DESIGNED developed fibula
FOR PERCHING on its lateral face.
Found on hummingbirds,
kingfishers, ovenbirds,
and nightjars. They have
small feet, with
GREAT CRESTED
GREBE (Lobed Toes)
In some swimming
the second, birds, the toes look
third, and like oars. They have
fourth toes BIRD LEG HUMAN LEG agora wide
joined together. This border.
makes it possible for
them to stand still.
Thigh
THE FOOT II
The distal tarsal
bones merge into the
metatarsal bone and
create tarsometatarsal
bones.
FEET DESIGNED
FOR RUNNING
Found on bustards,
curlews, and rheas. They
have long legs with short
toes. The hallux and
the fourth toe
are very small,
which decreases
Tibia
Tarsus and
Metatarsus
contact with the ground ANKLE Metatarsus
while running. Also known asa —
false knee
because it looks Internal/External Structure
Toes 1 (hallux)
and 2 have three
phalanges, toe 3 ~
has four, and toe
4 has five. "
Adaptation to Treeso—
The common waxbill
perches and sleeps on trec =
branches without expending much
energy. The weight of the body alone
causes its toes to close tightly
around the branch.
like a knee that
flexes backward. Birds walk on their toes, ours, is higher up and works like a SCOTS DUMPY.
Inreality, it is which form the first portion hip. It is located close to the body, |. ---— AOOSTER (Spurs
TRICOLORED HERON the ankle. of their feet. The second portion is and-ithelps'tomairitain balance... @
Its feet have long, thin toes that FE SE formed by the-tarsometatarsus. Its The thigh bon@'also stabilizes the
an top part is connected to the tibia, bod ddin the
on e
it hrough a joint similar to that of our _ skeleton. All the movements «
“ ad ankle. That is why the leg flexes these bones are controlled by
Oquimbo in Chile. backward. The knee, equivalent to tendons and muscles.
The Art of Flying
irds move in the air the same
way a glider does, that is, by
making the most of air
currents to gain height and
speed while moving. The
SS =
~~ ~
SSs SST
>
SSE :
shape of the wings varies according
to the needs of each bird group.
Some cover considerable distances
and thus have long, narrow wings,
whereas others have short, rounded
ADAPTATIONS TO RENEW IS TO LIVE
FEATHERS GLIDING
WINGS TO FLY FLAPPING FLIGHT
TAIL TYPES SPEED RECORDS
————> = OO =
~ : ~ = . ~~ —— = ——— =, ee, . -_
Feathers are usually renewed once a
year, and this process is as vital to
birds as feeding.
wings that allow them to make short
flights from branch to branch. Birds
also have shiny, colorful feathers that
males frequently use both to attract
females and to hide from enemies.
THE ART OF FLYING
daptations
here are three main theories to
explain why birds developed the
ability to fly. The evidence that
supports each of them tells a story of
adaptations to an aerial world in
which the fight for food and survival
is key. One reasonable theory argues
that birds descended from an extinct line
of biped reptiles that fed on plants and used
to jump from branch to branch to flee.
From Reptile to Bird
It is known that several evolutionary lineages
from both reptiles and birds did not survive the
evolutionary process, and that the lineage that truly
links these two animal groups has not yet been found.
However, some theories state that the change from
reptile to bird took place through a long process of
adaptation. There are two arguments and a variant:
the arboreal theory, which posits an air-ground flight
model; the cursory (or running) theory, which focuses
on the need for stability when running; and a variant,
related to parental care, which posits that dinosaurs
started to fly as a way of keeping their eggs safe.
This theory, the most accepted for a long time, states that flight was an adaptation to
the environment in which certain herbivorous climbing reptiles lived. At first, dinosaurs
developed a kind of parachute to protect them if they missed a branch when jumping, and
later it became a way to move from tree to tree. Finally, flight evolved to involve the
flapping of wings, which allowed the animal to cover greater distances.
CLIMBING
The evolution of
dinosaurs yielded
climbing species.
This variant proposes that
reptiles started to climb trees
to prevent their young from
becoming prey. Gliding removed
the need to climb out of the trees.
JUMPING
GLIDING
Flight made it possible to
move from tree to tree
without using the ground.
Adapted to aérial life,
they jumped from
branch to branch.
FLAPPING
Gliding was
improved to
cover distances
and increase
agility.
Supported by good fossil evidence, the running theory argues
that birds descended from certain bipedal dinosaurs that were fast
runners. Their arms opened, evolving into wings, to stabilize them
as they jumped. Progression from this development to flying
was simply a matter of time.
RUNNING
Their two legs
enabled them to
run at high speeds.
JUMPING
As they jumped high,
their wings stabilized
them, allowing them ji
to catch prey. :
Iq
5. FLAPPING.
After developing the
ability to jump and
glide, these reptiles
started flapping to
cover greater distances.
he.tipsof the wi 1
propel flight; the arms
support the bird;‘and:the
shoulders enable the
flapping movements.
The bones are
extended and
reinforced; then
they merge.
Highly
Mobile
Shoulder
Emergence of the
Tarsometatarsus
The shoulders can
perform a wider
range of movements.
The fingers merge.
Rotary
Shoulder
Three Fingers
Dinosaur arm with
Z pincer claw and
limited movement
Limited
Shoulder ~ Five
Fingers
Short Arm
It evolved from an arm with a talon into a
limb, without a talon, that was adapted for
flight. The causes of this change are not yet
clear to scientists. However, fossil records
show how bones merged until they reached
their present forms.
BIRDS
Flying
Squirrel
Flying
In flying animals, from primitive pterodactyls to bats, Gecko
wings have always been a flap of skin. A tear creates
serious problems because it takes time to heal, and the
wing may be misshapen afterward.
Feathers are a unique evolutionary
advantage. Their versatility, strength,
individual nature, and ease of
replacement make them an ideal
adaptation to flight for
vertebrates.
FEATHERS
Today found only on
birds, feathers are
scales partitioned into
three smaller sections.
They form a light,
uniform, resistant
network that covers
the whole body.
MODIFIED
SCALES
They became
divided into
smaller sections.
LARGE
SCALES
Several dinosaur
species had them.
The development of feathers brought great
advantages to birds because feathers enabled
them to fly. Feathers evolved from scales, and
they are made of the same material. Feathers
keep the body's temperature constant and
are lighter than scales.
SCALES
Resistant, they
covered the body
of dinosaurs.
In its maneuvers, this
great hunter displays the
entire evolution of flight.
26 THE ART OF FLYING
Feathers
eathers are the feature that distinguishes birds from all other
animals. They make birds strikingly colorful, protect them
against cold and intense heat, enable them to move easily
through the air and water, and hide them from enemies. Feathers
are also one of the reasons why human beings have domesticated,
caught, and hunted birds. A bird's set of feathers is called its
plumage, and its color is essential for reproductive success. @
Structure
Ih The structure of feathers has two
(Leff parts: a shaft and a blade. The shaft is
called the rachis, and the part connected to
the bird's skin is called the calamus. The
movement of a feather is generated in the
rachis. The blade is composed of barbs that
branch into barbules. The feather's blade, in
which the barbules have a series of barbicels,
or hooklets, at the tip, is called a vane. The
interlocking hooklets in the vane create a
network that adds rigidity and resistance to
the feather. It also defines the characteristic
aerodynamic shape of feathers and helps
make the feather waterproof. When feathers
wear out, birds have the ability to replace
them with new ones.
INFERIOR UMBILICUS
The orifice at the base of
the calamus, into which
the dermic papilla
penetrates. New feathers
receive nourishment
through it.
Types of Feathers
© There are three main types of
Lal feathers, classified according to
placement: those closest to the body
are down, or underlying feathers; those
at the top are contour feathers; and
those on the wings and tail are flight
feathers, which are often referred to as
remiges (on the wings) and rectrices
(on the tail).
A swelling, or papilla,
1 develops in the bird's
skin.
In the papilla, special
(4 ‘
yy skin cells form a
follicle.
¢ A tube that will
3 extend from its base
and become a feather
grows in the follicle.
HOLLOW
INTERIOR
INNER PULP
OF THE SHAFT
CALAMUS
It provides the necessary nutrients for
feathers to grow. Nerve endings that
stimulate the feather's movement are
found at its base. This allows the bird a secondary rachis, the
to detect changes in its surroundings. hyporachis.
It contains some loose
DOWN y
These light and silky feathers» “AU
protect the bird against the ~~ sat =
cold. They have a short
rachis, or none at all. Their
barbs are long, and their 2
barbules lack hooklets. In ak Kas
general, down is the first type > ts
of feather that birds develop =“ ALK 3
when they hatch. a
\
SUPERIOR UMBILICUS
barbs. Some feathers have
RACHIS
A feather's main
shaft, similar to a
hollow rod
BARBS
are slim, straight
ramifications that
grow perpendicular
to the rachis.
CONTOUR
Also called covert
feathers, they are short
and rounded. They are
more rigid than down
feathers. Because they
cover the body, wings,
and tail, they give
birds their shape as
they fly.
EDGE
The edge presents
an excellent
aerodynamic
profile for flying.
WHAT IS KERATIN?
Keratin is a protein that forms part of the
outermost layer of a bird's skin, just as it does in
other vertebrate animal groups. Keratin is the
main component of feathers, hair, and
scales. Its distinct resistance helps
keep the hooklets woven together
in the vane. This allows birds'
feathers to maintain their shape
in spite of the pressure exerted
by the air during flight.
VANE, OR BLADE
Its outer portion
contains a great
number of barbicels.
»®
PREENING THE PLUMAGE
Birds need to preen their feathers with
their bills not only to keep them clean
and free of parasites but also to
keep them lubricated, which helps
birds resist inclement weather.
Birds touch their uropygial, or preen,
glands with their bills. Then they
distribute the oil and wax this
gland produces all over their
plumage. This task is a
matter of survival.
SELF-CLEANING
WITH ANTS
Some birds, such as certain tanagers,
catch ants with their bills and grind
them. They then oil their feathers
with the ground-up ants. It is believed
that the acid juices from the squashed
ants work as a repellent against lice
and other external parasites.
SPECIAL FEATHERS
Vibrissae are special feathers
formed by only one filament.
Sometimes they have loose barbs
at the base that perform a tactile
function. They are located at the Vibrissae
base of bills or nostrils or around
the eyes. They are very thin and
are usually blended with
contour feathers.
PTERYLAE AND APTERIA
At first glance, a bird's body is covered with
feathers. However, feathers do not grow all over
the body but rather in particular areas called
pterylae. This is where the papillae, which create
new feathers, are found. The shape and
placement of pterylae vary according to species.
Pterylae are surrounded by naked areas, called
apteria, in which feathers do not grow. Penguins
are the only birds whose bodies are completely
covered with feathers. This characteristic makes
it possible for them to live in cold regions.
POWDER DOWN
Filoplumes
birds. They grow
constantly and break off
at the tip into small waxy
scales. This “powder” is
preened into the
plumage to provide
protection.
IMPERIAL HERON
Powder down
keeps its plumage
waterproof.
This special type of feather
can be found on some aquatic
BIRDS 27
TRAILING
EDGE NOTCH
The turbulence
during flight is
reduced by this
notch, found
near the tip of
the wing.
DUST BATH
Birds such as pheasants,
partridges, ostriches, pigeons,
and sparrows perform dust
baths to control the amount of
grease on their feathers.
28 THE ART OF FLYING BIRDS 29
re Wing Size and
Gsm Loading
The wingspan is the
distance between the tips
of the wings. Together with
width, it determines the surface
area, which is an essential
WANDERING measurement for bird flight. Not
ALBATROSS Just any wing can support any
bird. There is a close
SSH relationship between the
(15m) animal's size (measured by
weight) and the surface area of
its wings. This relationship is
called wing loading, and it is
crucial in understanding the
flight of certain species.
Albatrosses, with large wings, ARGENTAVIS
have low wing loading, which MAGNIFICENS
makes them great gliders, (extinct)
whereas hummingbirds have to
flap their small wings intensely
to support their own weight.
The smaller the wing loading, the
more a bird can glide; the bigger,
the faster a bird can fly.
Wings to Fly
ings are highly modified arms that, through their
unique structure and shape, enable most birds to fly.
There are many types of wings; they vary by species.
For instance, penguins, which are flightless, use their wings
for the specialized task of swimming. Among all wings that
have existed in the animal kingdom, those of birds are the
best for flying. Their wings are light and durable, and in some
cases their shape and effectiveness can be modified during
flight. To understand the relationship between wings and a
bird's weight, the concept of wing loading, which helps explain
the type of flight for each species, is useful. —
Wings in the
Animal Kingdom
Wings have always been modified
arms, from the first models on
pterosaurs to those on modern birds.
Wings have evolved, beginning with the
adaptation of bones. Non-avian wings
have a membranous surface composed
of flexible skin. They extend from the
bones of the hand and body usually
down to the legs, depending on the
species. Avian wings, on the other hand,
are based on a very different principle:
PTERODACTYLS
still had talons, and
only one finger
extended their wings.
BATS
Four fingers extend
the membrane, and
the thumb remained
as a talon.
SECONDARIES
Thei b
the arm and hand form a complex of BIRDS ‘ Pareegesatly
skin, bone, and muscle, with a wing pie tusecmingets depending on the
form the tip of the
surface consisting of feathers.
Furthermore, the avian wing allows for
important changes in form, depending
on the bird's adaptation to the
environment.
species. They
complete the
surface.
wing where the
rectrices, or primary
feathers, are
attached.
TERTIARIES
Together with the
secondaries, they create
the wing's surface.
Types of Wings
According to the environment in which they live and the type of flight they
perform, birds have different wing shapes that allow them to save energy and
to perform efficiently during flight. The wing shape also depends on the bird's size.
Consequently, the number of primary and secondary feathers changes depending on
the needs of a given species.
LOOSE FEATHERS
Sometimes barbicels are
missing, and feathers on the
wing come apart, creating a
loose and ruffled appearance.
STERNUM
There are many Short feathers are OR KEEL
secondary feathers. located all over the wing.
The external
primary feathers
are longer.
The outermost primary
feathers are shorter
than the central ones.
They are wide at
the base, with
separate feather tips.
PRIMARY FEATHERS
Flying birds have from
nine to 12 primary
feathers. Running birds
may have up to 16.
Flightless Wings
Among these, penguins' wings are an extreme
case of adaptation: designed for rowing
underwater, they work as fins. On running birds, wings' FUNCTION
first and foremost function is to provide balance as the The wings of
bird runs. These wings are also related to courtship, as ostriches carry
FAST WING ELLIPTICAL WINGS WINGS FOR SOARING WINGS FOR SOARING WINGS FOR SWIMMING birds show off their ornamental feathers during mating GUL LAS
Remiges are large and tight to Functional for mixed flights, ABOVE LAND ABOVE THE OCEAN In adapting to swimming, the season by opening their wings or flapping them. Wings i ear
allow for flapping; the surface is they are very maneuverable. Wide, they are used to fly atlow — Their great length and small width —_ feathers of penguins became are also very efficient at controlling temperature, as Pun aten eer
reduced to prevent excessive Many birds have them. speeds. The separate remiges make them ideal for gliding short, and they serve primarily Rirdsucethontactonetonenilatatheirbedies GaietilD.
Fichon! prevent turbulence when gliding. against the wind, as flying requires. _as insulation.
Courtship Display
> The tail feathers of the female black grouse are
straight, whereas those of the male have a
half-moon shape. They usually keep the feathers
closed and near the ground, but during the courtship
displays they spread them out and show them off
completely. To finish the show, the male runs back
and forth in front of the female.
ver the course of evolution, birds' tail vertebrae fused into
a pygostyle, and in their place feathers of different sizes and
colors emerged. These feathers have multiple uses: they can
control aerial maneuvers during flight, work as brakes during landing,
and make noise. Males also use them during courtship to dazzle and
win over females. Usually the tail is formed by rectrices that vary in
number, length, and rigidity depending on the species.
OPEN CLOSED
RECTRICES
Tail feathers can wear out and fray becatise
of friction during flight or by brushing
against vegetation.
hy
-
| UNDERTAIL COVERTS
Feathers that cover the lower part of
* Black Grouse rectrices, protecting them against the wear
Lyrurus tetrix and tear caused by air friction
The male is recognized by its
bluish black plumage and the
red caruncle over its eyes.
The Key to 7
How It Works J ~
~~, yp The tail can perform a variety of functions
because of the movement and shape of the
Fan of Rectrices
y = feathers. The powerful muscles in the pygostyle
4 , a : prepare the plumage for courtship displays and for flight, i... ae
“ f . Feil ei Bess . On flying birds, it is light and FORKED TAIL N y ROUNDED
, ‘ & \ ie e a 4 Been aging On trees, arr * aerodynamic. On tree-climbing Found on swallows i ( TAIL
- Workcas rudders ia aaanniitic: birds, such as woodpeckers, the and frigate birds. Found on some
— plumage is rigid, which allows them to The external songbirds. The
ye OPEN CLOSED OPEN use it as a support (pointed tail). The feathers are very } \ central feathers
: Soe coverts of male peacocks are more long and look like are only slightly
so = developed than their rectrices so that Scissors. | longer than the
orn, the peacock can show them off. rN external ones.
|
. Y
. GRADUATED TAIL ( | } MARGINATED SQUARE
TAIL TAIL
ee I rie: I Se — ~ Found on trogons \ ) Found on blue jays. N Found on
The plumage ie body leans le spread-out tail ~ i Y ils. The tail
spreads out, and backward, and the feathers, together with an © + va i ae tail Lge -_ \ { y i, a ae, :
the main axis of tail closes. The intense flapping of the : Mee eS Se UNS UST y Silgiitly ( Re
the body is legs prepare to wings, make it possible for has a layered shape. shorter than the even-sized
positioned parallel grab the branch. the bird to slow down and a x external ones. feathers.
to the ground. prepare its body to land. e
BIRDS 33
32 THE ART OF FLYING
Order of
Massive replacement of chest, back, and
To Renew Is to Live
\ SON X head coverts occurs from the center
Replacement a . % outward. This change coincides with the
EF“ Many species start substitution of the seventh remex
ge é fe ; (singular of remiges).
he periodic renewal of plumage is called molting. It is the Ll molting, a process ALULAE ), “SS aps er ee a
Rectrices are replaced from the center
outward. This happens simultaneously
with the loss of tertiary remiges.
triggered by hormones, in a ‘
specific order. Molting starts :
with remiges and wing ~ ty
coverts, continues with
i in
replacement of worn-out, older feathers with new ones that are
in better condition. In a bird's life cycle, molting is as important
an event as migrating or caring for young. The beginning of this
phenomenon is determined by environmental factors that trigger a
series of hormonal stimuli in birds: they start to eat more and to
decrease their other activities. This, in turn, causes them to gain
weight through an accumulation of fat that will serve as the
source of energy for developing new plumage. e
rectrices, and finishes
with body coverts. This
gradual process
keeps the body
temperature
stable.
NEW FEATHER e)
The wing
coverts are
_ replaced.
Renewal starts in the first
primary remiges and
spreads outward. In the
olan OLD FEATHER secondary remiges, it
Renewing the plumage 6 l % spreads in two directions.
is important because it Replacement occurs when
Plumage Molting
IR The main function of molting is to replace worn-out
[Ll plumage. It also helps the bird adapt its appearance
to the seasons and to different stages in life. The renewal
can be partial or total. Some feathers are replaced before helps keep the bird's ; the new remiges are three
the spring, when the task is to attract a partner for oa ees Li elt raced pct fourths developed.
reproductive purposes. In the fall, before birds have to stable. It also keeps the HERE WURICIC IG 1s eeniC
start caring for their young, the renewal is complete. On
most birds, molting takes place in each pteryla, following a
determined order. Penguins, however, renew all their
feathers at the same time, within two to six weeks.
feathers in place while
the bird moves about,
and it helps the bird to
go Pkg by DEVELOPING
predators. PLUMAGE
BLOOD VESSELS
nourish the
feathers during
their development.
DERMAL PAPILLAE
A feather develops in
each of them.
SEASONAL CHANGE
In the high mountains, snow transforms the
landscape during winter. During this time,
nonmigratory birds exchange their summer
plumage for a winter one. This change helps
them to protect
themselves from
predators.
DEVELOPING
BARBS
FOLLICLE
EPIDERMIS
m,, NEW FEATHER
BEING FORMED
PTARMIGAN
The feather, now lifeless,
assumes its characteristic
blade shape. A residue of
dermal and epidermal cells
' . \ EPIDERMAL at the base of the follicle
" @ COLLAR forms an area that will
SUMMER WIN ~S The rapid growth of the Malpighian allow for replacement when
PLUMAGE PLUMAGE a layer starts to develop the new the feather wears out.
The feathers The new, @ The papilla grows and becomes layered. The feather. The rachis, barbs, and barbules
have deep unpigmented outermost layer is covered with keratin, which become keratinized. The vessels that
pigmentation. feathers make it A papilla develops from skin cells. The protects the underlying Malpighian layer (nucleus bring nutrients are reabsorbed, and the da S
This helps birds possible for In the epidermal papilla, the epidermal cells multiply faster than the of the papilla). A group of dermal cells brings connection with the dermic layer is
blend in with the ptarmigans to blend formation of the new feather causes dermal ones and form a collar-shaped nutrients through the blood vessels that travel closed. Finally the protective vane IS THE AVERAGE AMOUNT OF TIME THAT
vegetation. with the white snow. the detachment of the worn-out one. depression called the follicle. along the new feather. breaks, and the feather unfurls. IT TAKES FOR A NEW FEATHER TO FORM.
34 THE ART OF FLYING
Gliding
nvolves using air currents to fly and save energy when traveling long
distances. There are two types of gliders, terrestrial birds and marine
birds, each of which is adapted to different atmospheric
phenomena. Terrestrial birds rise on thermals (rising air currents).
Marine birds make use of oceanic surface winds. Once the birds
gain altitude, they glide off in straight paths. They slowly lose
altitude until encountering another thermal that will lift
them. Both terrestrial and marine gliders have wings of
considerable size. e
TYPES OF GLIDING FEATHERS
Terrestrial Glider
A large wing surface allows
it to make the most of
rising air currents at
moderate speed.
Marine Glider
Thin and long wings allow
it to make the most of the
constant surface winds and
offer less resistance to
forward movement.
Takeoff
I Usually, a powerful jump followed by the vertical flapping of the wings
[Le is enough to make a bird take flight. As it descends, the tip feathers
are stacked on top of each other, forming an airtight surface that helps drive
the bird upward. As the bird raises its wings to repeat the movement, the
feathers curve and open until the wing reaches its highest point. With a
couple of flaps of the wings, the bird is in flight. Bigger birds need a running
start on the ground or water in order to take off.
Fast and Strong
Flapping
During the
upward movement in
~ wing flapping, the primary
_feathers open up, offering less x
resistance t tot the air.
10%
THE ENERGY
SECONDARY SAVED BY A
FEATHERS SEAGULL WHILE
GLIDING
There are many
of these because
of the wing's
length.
The wing length of
some pelicans may reach
8 feet (240 cm)
from tip to tip. MOVING
FORWARD
PRIMARY
FEATHERS
There are
fewer of
these, as
they only
form the tip.
CONTINUOUS AIR
WINGLETS
Terrestrial gliders usually have
separate primary feathers (toward
the tip of the wing) that serve to
decrease the noise and tension
generated there by the passing of air.
Modern airplanes copy their design. ws
The tip feathers work
as airplane winglets.
Airplane Winglets
are made of one or
several pieces.
BIRDS 35
Marine Birds FLIGHT PATTERNS
Fl Dynamic soaring is performed by birds with long and thin wings, such as Flying in formation is a way for birds in wake. There are two basic patterns: “L”
Ll the albatross. These wings are designed to take advantage of horizontal flapping flight to save energy. The leader and “V." The first is used by pelicans, and
air currents, which are responsible for the formation of waves in the ocean. The encounters more resistance as it flies, the second is used by geese.
result is a flight consisting of a series of loops as the bird is lifted upward when while the others take advantage of its
it faces the wind and moved forward when it faces away from the wind. This “L"” FORMATION
kind of flight can be performed at any time. a aay awa Leader
maa ~ The leader makes the most
% effort, as it “parts” the air.
- WEAKER Rel
> WIND eray, = The Rest of the Formation
When the leader gets The other birds make use
tired, another bird takes < the turbul Air
its position. 10) je turbulence Pro uce
by the leader's flapping to
ae <== gain height, following along
behind.
Dynamic soaring o> Bd
/ allows birds to cover l A of a “v" FORMATION
4 eiae oi long distances in the 0) or ~~ The principle is the same, but
lirection they desire. i i
direction they desire THE PERCENTACE OF the birds form two lines that
STRONGER -~ converge at a point. This is
WING FLAPPING THAT th lf ti db
WIND 3 to 33 feet (1-10 m) é usual Tormation user Ny
is the range in altitude for dynamic soaring. GEESE SPARE THEMSELVES geese, ducks, and herons.
Sw a BYE esanibermen nor,
SPEED OF
DISPLACEMENT
depends on the strength
of the headwind.
THE WING
Its particular shape causes
lift, with its convex side
and less pronounced
concave side.
©— PATAGIUM
r Elastic and resistant skin covering with feathers.
It is the wing's cutting edge, responsible for
dividing the airstream.
FASTER
AIRSTREAM UPPER SIDE
Convex. The air covers more distance and
accelerates, causing a lower pressure that
“sucks” the wing upward.
CONSTANT
AIRSTREAM LOWER SIDE
Concave. The air covers less distance, it does not
accelerate, and its pressure does not change.
TERRESTRIAL BIRDS Ascent Straight Gliding Descent Ascent
ee » When birds find a warm Once the maximum The birds They rise again when
They use warm, rising air currents air current, they gain possible height is slowly glide they encounter another
generated through convection in height without having to gained, the birds glide downward. warm air current.
flap their wings. in straight paths.
Thermal: Pie —e ~4
Hot Air 7 a = = ai
* Cold Air Seo? g 7 Warm Air
Current
the atmosphere or through the
deflection of air currents against crags
or mountains. Then they glide in a
straight flight path. This type of flight
_is possible only during the day.
36 THE ART OF FLYING
Flapping
Flight
ost flying birds use flapping flight all the time. It consists of moving
through the air as if rowing with the wings. With each flap (raising
and lowering), the wing both sustains the bird in the air and
pushes its body forward. There are different types of flapping flight and
different rates of flapping. In general, the larger the bird, the more
powerful and less frequent its flapping will be. Because flapping is an
activity that consumes much energy, birds have adapted a variety of
flight patterns: some, like hummingbirds, always flap their wings, >
whereas others alternate flapping with short-term gliding. The wing &b
shape also varies according to the bird's needs. Birds that cover long
distances have long, narrow wings; those that fly among trees have
short, rounded wings. @
THE HEAD
Tilted backward to bring it
closer to the center of
gravity (between the wings)
and attain balance
ANGLE OF THE WIN
the wing's position. It
WAVELIKE FLIGHT PATH
Ideal for high speeds, it consists of flapping
the wings to gain height and then folding
them in order to descend along the flight's
trajectory. Afterward the bird flaps its
Propulsion
The bird flaps its wings to ascend.
Variable, depending on
closes on the downstroke.
G
wings again, making use of the inertia of
its descent to regain height. A variation of
this type of flight involves gliding between
flaps of the wings.
»
Ascent Flapping Wings
THE TAIL
Slightly curved, it
works as a rudder
during flight and as
a brake during
landing.
THE LEGS
remain at rest until
landing. They stay very
close to the body.
THE BILL
Projected =
forward, its miles
aerodynamic per hour
shape decreases
the bird's air
resistance.
(50 km/h)
THE AVERAGE SPEED OF AN
ADULT PELICAN DURING
FLIGHT ON A WINDLESS DAY
A Specialized Design
IR Flapping flight is an activity that requires much
[La effort. Therefore, birds must eat large amounts of
food. A migrating swallow uses 4 kilocalories (4,000
calories) per 1.6 miles (2.5 km) of flight, whereas a small
mammal needs only about 0.025 kilocalorie (25 calories)
to travel the same distance.
Rest
The bird keeps the wings near its body
to save energy for short intervals.
Folded-up Wings Descent
oD
Upstroke
the remiges separate and
form grooves to reduce
friction. Support for the
bird comes from the
patagium, a layer
of skin that
anchors
the feathers
and covers
the bones.
THE CROP
Made of elastic
skin. It can hold
food during flight.
WINDMILL FLIGHT:
HUMMINGBIRDS
Hummingbirds are able to hover in order
to suck the nectar out of flowers. In
contrast to other birds, hummingbirds'
wings are attached only at the shoulders,
which provides greater freedom of wing
movement, allowing the hummingbird to hold
itself in the air during both the upstroke and the
downstroke. The hummingbird has to flap its
wings up to 4,800 times per minute during
directional flight and for hovering.
2
Pe pe tr
_— aed 5
le - --2
Ysa er x -’
e Diagram describing the
‘ bf m
Lif movements of the tip of the
wing during flight
The wings flap 80 times per
second during normal flying.
Courtship Display
Certain hummingbird species can
flap their wings up to 200 times
per second during courtship.
STRENGTH
To gain height above
the ground, the wings
flap in big arches in a
manner that generally
produces a lot of noise.
As the wings move upward,
WING STROKE
The wing acts like
an oar as it traps
air and pushes the
bird forward.
The wing has
short, sturdy
bones; the
muscles are
very powerful.
-
ft? Great
' Maneuverability:
Hummingbirds are the
WY only birds capable of
moving backward.
BIRDS 37
@
Downstroke
As the wings move
downward, the remiges are
forced together, and the
wing moves forward a little
for extra support. The wing
also bends at the tips to
push the bird forward,
as if it were rowing.
Muscular strength is
distributed to the
entire wing, but it
increases near the tip.
The downstroke of
the wing provides
propulsion.
Landing
IR requires reducing speed until the bird becomes motionless and
[Laff settles. The bird faces the wind and spreads out its tail, wings, and
alulae (bastard wings, characterized by their stiffness and growth from
the first digit), while lifting up its body and extending its legs forward to
increase the surface area in contact with the air. In addition, the bird
flaps its wings intensely in the direction opposite to its flight. Everything
works like an aerodynamic brake. Some birds—such as the albatross, with
its long, narrow wings—tend to have problems slowing down. As a result,
they are ungainly when landing on the ground, but on the water they are
able to ski on their feet until coming to a stop.
Flapping Against
the Wind
Sliding The feet spread open
before landing to provide
more resistance and help
the bird to slow down.
38 THE ART OF FLYING BIRDS 39
Speed Records
RUPPELL'S
he world of birds is amazing when expressed in numbers. Most birds oe ae
a travel at speeds between 25 and 45 miles per hour (40-70 km/h), but 36,870 feet
when diving, peregrine falcons can reach more than 200 miles per hour (11,237 m) .
(320 km/h). Many species can reach an altitude of 6,600 feet (2,000 m), In 1973 a Ruppells griffon 15-20 pounds 136
although climbers have seen geese flying over the Himalayas at more than ura a oe
26,000 feet (8,000 m). The fastest swimmer is the Gentoo penguin, which Ivory Coast at this altitude. ich a
reaches 20,000
feet (6,000 m).
can swim 22.4 miles per hour (36 km/h). Considering its small size, it is
surprising that the Selasphorus rufus, or Rufous hummingbird, which is only
4 inches (10 cm) long, carries out an extensive round-trip migration each year
34,5
from northern Alaska to Mexico. Here are some more incredible facts. @ ——79-#t (2.4. m) —
33
Air ALTITUDE > apni tease rn BAR-HEADED GOOSE CHOUGH
Flying at high altitudes OF ALTITUDE : 28,000 FEET (8,500 M) 29,030 FEET
requires a strengthened according to a pilot who onne climbers reported + scitehe :
SPEED P cireulatary-systemi to itnesced asaociciee having seen specimens of A group of climbers
make up for the scarcity ie Hebrides Islands geese flying at 28,000 feet on Mt. Everest found 31,5
Most birds fly of oxygen in the air. (8,500 m) over the choughs standing on
between 25 and 45 ena Himalayas. the summit.
miles per hour (40 miles per
and 70 km/h), but hour) _ |
the fastest birds can 0
beat the cheetah, the
most famous of the
pie x
fast animals.
Qe KM/H) =
DRAGONFLY SN od “at
The fastest flying os oe >.
insect. It reaches we ; >: x ‘i 28,5
3 ] mph STARLING eres
50 km/h). _38 MPH
( ) /~ (60 KM/H) 75 MPH
(20 KM/H) "] yl?
a *
= A
PHEASANT STORK -
31 MPH 47 MPH a
(50 KM/H) (75 KM/H) ROYAL SWIFT
99 MPH
7 (60 KM/H) am
ROYAL EAGLE
81 MPH
d Scale
Lan cn
per hour)
Land-Water (130 KM/H)
santana nian SPINE TAILED SWIFT
¢ /H) 106 MPH (171 KM/H)
P Fastest in muscular flight.
a i a
ye PEREGRINE FALCON
ee é BY Weight of Males
Z we 200 mph 1.1-2.4 pounds (0.5-1.1 kg)
(3820 knv h) Weight of Females
HARE FASTEST BIRD 1.5-3.5 pounds (0.7-1.6 kg)
20 MPH WHILE DIVING :
(32 KM/H) a5
its)
28
— 32-451
GIRAFFE (80-115 cm)
30 MPH
(50 KM/H)
P| OSTRICH
fi 45 MPH (72 KM/H)
ater ibe nerd Fastest running bird CHEETAH
= 100
DOLPHIN
PRONGHORN 65 mp h
22 MPH
(5 KM/H) 55 MPH (88 KM/H) (105 km/h)
Fastest mammal over FASTEST MAMMAL
long distances OVER SHORT DISTANCES
oO
oe
{ z TUNA
SEL WHALE PR 62 mph
30 MPH (48 KM/H) Sane
29 Fastest swimming ar ; (100 knv/h)
mammal D FASTEST SWIMMING FISH
GENTOO PENGUIN Pa ° OVER SHORT DISTANCES
22.4 MPH (36 KM/H) 38 y
Fastest swimming bird
SAILFISH
DISTANCE I 50 MPH (80 KM/H)
The arctic tern travels
: ENDURANCE
24,850 miles
The endurance record
(40,000 km). goes to the golden
It migrates from Canada and plover, which is able to
Labrador to Antarctica and Fa DISTANCE IT fly a distance of
the Austral Sea. On each trip, The Rufous hummingbird ;
it travels 9,000 to 12,000 flies from northern Alaska RUFOUS HUMMINGBIRD 1 p) 900 miles
miles (15,000-20,000 km). to Mexico and back—a (Selasphorus rufus) (3,000 km)
: ¢ : é
ARCTIC TERN Ura dee : without stopping.
(Sterna paradisea) 6 000 mile Ss Weight
) 0.1-0.2 ounce GOLDEN PLOVER
(10,000 km/h). (4-6 g) (Pluvialis apricaria)
The Lives of Birds
———
he behavior of birds is closely
connected to the seasons. To
survive, birds must prepare for
the arrival of fall and winter
and adjust their behavior
N \ \ .
ae
i ass
V8
7 ms ~
’ * “ns ~
pte ee
~ eee. S
accordingly. Gliding over the oceans, a
wandering albatross, for example, can
travel anywhere from 1,800 to 9,300
miles (2,900 to 15,000 km) in a single day
in search of food. When the time comes
we,
to choose a partner, the behavior of
males is different from that of females:
males employ a variety of tactics to win
over females and convince them of their
fitness. Some bird couples stay together
THE ANNUAL CYCLE BIRTH IN DETAIL
HOW THEY COMMUNICATE POSTNATAL DEVELOPMENT
NUPTIAL PARADE A DIET FOR FLYING
HOME SWEET HOME MIGRATION ROUTES
FIRST, THE EGG DEFENSE STRATEGIES
forever, whereas other birds change
partners every year. As for caring for
chicks and building nests, in most
species both parents participate.
THE LIVES OF BIRDS BIRDS
The Annual C cle 7 Survival Manual (Sula nebouxii) The males—and, on occasion, the
i H i i females—perform a graceful courtship dance
Birds' most striking behaviors are associated with the
reproductive season. During courtship parades, birds engage in after veins be poe for ae They Raised Head
is |j i i i i elaborate choreographies; there are also extraordinary fights between SING ANG SOW. Oui Clele PUMages With It flaps it:
he annual cycle of SEASONS is like the daily cycle of night and day. Fluctuations mn the “ males. The blue-footed booby, the male frigate bird, and the ruff are just a careful synchronization. neon
intensity of light over time create a series of physiological and behavioral changes in birds, few exaniples of binds that engage in these behaviors: Others such asthe marches
i ] i i snowy egret (Egretta thula), prefer to offer twigs for the construction of looking at
BI at geet areca ner ace ener aire Slt ea =
° leaves, flowers, or any other object that may help him to win over the
the secretion of melatonin by the pineal gland. The blood level of this hormone acts on the Temale. Diels perlormaicesae not conncsied only wo courtsip. Te
. - eyes killdeer (Charadrius vociferus) fakes being wounded to defend the eggs or
hypothalamus-hypophysis axis, which regulates internal processes. This is one reason why birds chicks in the nest from predators. It offers itself as easy prey by dragging a
start to change their plumage and feel the need to fly to other areas. wing as if it were broken. This trick shifts the danger away from the young.
The magnificent frigate bird (Fregata _ bill. During the reproductive season,
How the Hypophysis Works magnificens) is a large bird that lives _it is responsible for building the nest.
se x as ae in coastal areas. It has large wings, With its impressive appearance, it
Reproduction is the main activity under the control stimuli and produces hormones. These hormones , powerful talons, and a strong hooked — endeavors to attract a female.
of the hypophysis, which determines behaviors such regulate the metabolic activities that cause birds’
as finding a place to court females and mate, building a internal and external sexual organs to develop. For
nest, incubating the eggs, and stimulating unborn chicks to example, the gonads become enlarged, and secondary
break their shells. The hypophysis is a gland in the brain sexual characteristics, such as ornamental crests or
that has several functions. It receives nervous and chemical _ plumes, appear.
New House Red Chest
; While it prepares The throat pouch
DORSAL VIEW VENTRAL VIEW the nest, its chest remains inflated
ENCARGED OREM rests, with its skin | for several hours
Olfactory Pak SPN \ . lawl pink and relaxed. or until the female
Pa Cerebral Hemisphere \ . \ r chooses the most
‘ ppm al seductive male.
AX Optical Chiasm ——\—_y : f Parade
SY GELS é Optical Lobe \ ) Sle ; ‘ It lowers its head and
~ y Hypothalamus an, ae The pineal gland, or epiphysis, produces cater a a
Wis Cerebellum VYIY melatonin. The level of this hormone ce tia it shakes its whole body.
determines the phases of sleep and
wakefulness.
pelican reclines
its head and é ve
places its bill
under a wing.
Medulla Oblongata
Infundibulum and Hypophysis
In the summer, male ruffs develop a
huge “ruff” and auricular feathers
around their necks. Their courtships
are violent and striking. When
competing for mating
territory, they struggle
fiercely. Afterward
they docilely s
sprawl their = =
bodies on the
ground until the
Litt ; ; : female chooses the
id Wi lucky one.
Mh WH
Incubation, migration, and [ iif | I {
The hypophysis is located in the ventral area of
the brain, below the hypothalamus. Its secretions
control vital functions, from blood pressure and
the balance of water and salts in the body to the
activity of the gonads and the thyroid.
j r Lhe j | , , : J \ Ww. ™ .
; f ' ; APT 4 oN » Male Ruff
j Se — Philomachus pugnax |
The arrival of the first days a : ™ - = — \
of fall coincides with a — , \ \
decrease in the amount of , : ’ ‘ ;
In early summer, light. The migration season The amount of light increases
incubation takes place. The begins. with the beginning of spring;
increase in the amount of males use their htge throat
courtship activities vary \
according to the amount of lig |
available during each season.
daylight coincides with this pouches to court females.
phase of the annual cycle.
44 THE LIVES OF BIRDS
How They Communicate
ound is an important form of expression in the lives of birds. Birds' sounds
can be of two types: calls and songs. The former have a simple acoustic
structure, with few notes. They are associated with coordinating the activities of
a group, establishing communication between parents and their young, and maintaining
contact between birds during migration. Songs, on the other hand, are more complex in
rhythm and modulation. They are controlled by the sex hormones, primarily the male
hormones. For this reason, males produce the most varied melodies. Songs are linked to
sexual behavior and territorial defense. In general, birds either inherit or learn them. —
THE SONG AND THE BRAIN
Birds have a brain that is well developed for this function.
Testosterone acts on the upper vocal center of the brain, which
is in charge of memorizing, identifying, and transmitting the
orders for the execution of the song.
HIGH VOCAL
CENTER
It is controlled
by the central
nervous system
and orders the
bird to sing.
ROBUST
NUCLEUS OF THE
ARCHISTRIATUM
Tt sends the
information to the
muscles of the syrinx.
NUCLEUS OF THE
HYPOGLOSSAL NERVE
It controls the motor
functions of the syrinx.
THE PRODUCTION OF SOUND IN THE SYRINX
The participation of both the sternotracheal muscles and five to
seven pairs of small internal muscles is needed for producing
sounds. These muscles control the elongation and contraction of
the syrinx, which varies the pitch of the sound. The air sac is also
important because it adds external pressure, which causes the
tympaniform membranes to tighten. The esophagus works like a
resonating box, amplifying the sound. The articulation of the
sounds occurs in the buccopharyngeal cavity. There are two types
of articulation: guttural and lingual.
SONG-PRODUCING SYRINX
AIR AND TRACHEA CLOSED
BRONCHI MEMBRANE
During breathing, The membranes close
the songbird on both sides, under
maintains pressure from the
airflow without G S) external muscles. The
affecting the bronchi rise
resting syrinx. slightly and
9 ° also adjust the
membranes.
BRONCHI “a 4
EXPULSION OF AIR TO THE BRONCHI
The air stored in the air sacs and lungs is expelled. As it passes
through the syrinx (located between the bronchi and the
trachea), it vibrates the tympaniform membranes. These
membranes are the equivalent of vocal cords in humans.
TRACHEA
SYRINX
BRONCHI
DIVERTICULA TO
THE PNEUMATIC
BONES
LUNGS
AIR SACS
SIMPLE SYRINX
The tympaniform
membranes are located
above the place where
the bronchi divide. They
| ,
= VIBRATION Ly
are moved by a pair of OFTHEWALL =—
external muscles. y ‘ ]
7 MUSCULAR ACTION
ind ¥ p ’
TYMPANIFORM MEMBRANE
a BRONCHIAL RINGS
Strengthening Ties
BRONCHIAL
RINGS
r . os and female may participate.
, THE SOUND ys Some songbirds develop very complex singing rituals. The
PESSULUS He ace duet is perhaps the most striking because it requires both a
ee o—_ shared repertoire and good coordination between both birds. In
air current and — . d P
2 pecans propagate the ee cantor general, the male initiates the song witha repeated introduction,
sound through 1 | Membrane the female then alternates with different phrasing phrasing
ma the trachea allows for more or less cyclical variations that make it unique. It is
C Pied gg <— believed that this strengthens ties between the pair (as
» demarcation of territory does) and serves as a stimulus for
‘cooperative behaviors, such as nest building, in which both the
Territoriality and Range
> One of the most studied functions of birds’
songs is territorial demarcation. When a
bird occupies a territory, it sings to announce its
claim to competitors, as the pipit shown to the
left is doing. When birds must share territory, as
in a colony, they develop dialects (variations of
sounds produced by the species). When a bird
4,00
_{ HUMMINGBIRDS,
:
“7
w
FREQUENCY IN KHZ
+o
°
SHARE WITH HUMAN BEINGS
AND WHALES THE NEED FOR
“SOMEBODY” TO TEACH THEM SOUND INTENSITY
. TO VOCALIZE (SONGBIRDS,
PARROTS ARE EXAMPLES).
. \ '
Ww, ~ DISTANCE 131.2
BIRDS 45
*
born and raised in one location moves, it must
learn the dialect of the new location in order to
be accepted and participate in the community.
There are also mechanical sounds produced by
wing strokes, legs, and bills. In a display of
territorial defense, the eared nightjar combines
singing with beating its wings.
vi
[
w
bird .
species
DECIBELS
AND
54,050 COVERED SURFACE
SQUARE FEET
y INTENSITY
can vary widely from bird to bird.
The larger the territory, the greater
its reach. Its frequencies can change
* as well: the lower the frequency, the
“Se . greater the coverage.
q 2 . 3 TIME (IN SECONDS)
46 THELIVES OF BIRDS BIRDS 47
Nuptial Parade frat a nd 5.9 feet
place before copulation, although it can continue to occur thereafter.
(1.8 m)
IS THE SIZE OF THE TAIL OF THE
Postnuptial
With this display,
the great crested
Prenuptial
Prenuptial courtship
starts with territorial
inding a mate is not easy for any species.
For birds, the exhibition of plumage with a
bright colors, the presentation of —— Be fora ries Sncinnienertie. PEACOGK WHEN IT UNFURLS |
offerings and gifts, and the performance of a i elias the eee FEATHERS AND FORMS A FAN TO
dances and highly elaborate flight patterns are ATTRACT THE FEMALE.
some of the particular behaviors seen during
this period. They are known as nuptial or
courtship displays. The male resorts to all these a
strategic gestures to attract the female's attention
and prevent her from paying attention to other
males. Some of these rituals are extremely =
complicated; others are very tender and delicate. © a
tit
‘i a _-77 MUTUAL DANCES
vA \ e . ee AND COURTSHIPS
oe a i Great crested grebes (Podiceps
A ‘ ; cristatus) perform incredible i of scape ae
When ited i \ f aquatic dances. They bow to each eralerenesinerione
arousal peaks, Re X of other, dive, and run through the courtship dance
the male northern we water side by side. consisting of a series
harrier (Circus of impressive leaps.
cyaneus) flies in
a wavelike 2. “4
pale. otra a. a Be Special Courtship ;
ie os Le Avian courtship is a phenomenon that, depending on the
a ae va species, can take the form of various rituals. Lek rituals are
/ SK hy one of the most intriguing forms of courtship. The males gather
a : in a small area, called an arena, where they perform their i Emperor Penguin
- + courtship displays for the females. The females form a circle Aptenodytes forsteri
AERIAL EXHIBITIONS around the arena and end up mating with the male that has the A monogamous species.
B Certain birds, such as goshawks most striking secondary sexual characteristics. Lek is a system er Miitioice ond
Buring ~*~ or male northern harriers, court controlled by the dominant male, who ends up mating with most couples a spend their
courtship, the female in flight. They ascend of the females (polygyny). The less experienced males will mate entire lives together.
with only a few, or even none, of the females. For some species,
lek rituals can be very intricate. At least 85 species perform this
special type of courtship ritual, among them manakins,
pheasants, cotingas, and hummingbirds. Manaldigior
example, stand in line and wait their turn to pe
the male in the air in broad circles, only
hai a tae to let themselves fall in daring,
the female. sharp dives.
Monogamy or Polygamy
be Monogamy is the most common mating system, in which
& es two birds, one of each sex, participate, leading to the
; . formation of a couple. This couple can endure for a single
4 ¥ reproductive season or for life. Polygamy is an alternative
4 - " pattern, butit is not very common. Polygamy is divided into two {
' x classes: polygyny, in which the male mates with several ;
DISPLAYING BUILDING . awit i
PHYSICAL ATTRIBUTES BOWERS Another courtship strategy is So As : pa i ita Pe gt A ie, *
To find a partner, birds such as the snowy Australian bowerbirds build a the presentation of gifts. Male . Ma ; . : - harem). In eae partner has the sole responsibility of
egret resort to a series of very elaborate structure called a bower, which eagles give females prey, and » 4 - ; ’ caring for the eggs and chicks. There is also an exceptional case —
signals, such as songs, poses, dances, they decorate with pieces of European bee-eaters offer _ within polygamy: promiscuity. In this arrangement, a couple is not
flight patterns, noisemaking, and displays paper and fabric that inevitably insects. These offerings are . P ’ __ formed, and the relationship is limited to copulation.
of their ornamental feathers. attract the female. called courtship food. ; ‘
48 THE LIVES OF BIRDS
How the Nest Is Built
A cup-shaped nest is built at a fork between two or three branches. The
bird arranges twigs, grass blades, and small sticks, as if building a
platform. The bird then interlaces some of these materials with the tree to give
the nest solidity. It then interweaves the materials in a circular pattern. As the
nest takes shape, lighter, more adhesive materials—such as mud,
spiderwebs, caterpillar silk, and certain plant fibers—are used. Although the
outside is rough, the inside is lined with feathers for softness and warmth.
In general, if both the male and female participate in the construction, a
few hundred trips are enough to complete the nest. In some species, such
as weavers, males have to display a nest during courtship; in others
(African black eagles, for instance), the same nest is used every year.
ome Sweet Hom
ost birds lay their eggs in a nest, where
they are incubated by the body heat of
an adult sitting on them. To build a
nest, the couple normally uses mud
mixed with saliva, small stones,
branches, and feathers. When the
nest is in a visible location, the bird
covers it with lichens or loose twigs
to hide it from predators. Nest
shapes vary according to the bird wala
group: they can take the form BY,
of a bowl, a hole in a tree
(woodpeckers), or an excavated
burrow on a slope of sand or soil.
There are even birds that use
nests built by other species.
Des
builds solid nests, weaving
together leaves and grass blades.
Sometimes the male builds
several nests before the female
chooses him.
BASE
The bird gathers
branches and small
sticks on a fork to lay
the foundations of the
nest, setting up a
platformlike
structure. The bird
then ties it to the
tree, making it sturdy.
SHAPE
The bird intertwines
grass blades, small
sticks, and hairs;
fastens them; and gives
them a circular shape.
As construction
advances, the bird uses
adhesive materials,
such as spiderwebs.
SOME VARIATIONS
= :
a
snest's-.
dation, and-it 52) END
v if
WOVEN NESTS
Weaver birds intertwine grass
blades until they form a structure.
The entrances are underneath.
see ge
BURROWS
Parrots and kingfishers dig
their nests in sandy river
banks.
RY
|
|
|
PLATFORM NESTS
The sparrow hawk gathers a large
number of branches and assembles
a high, solid base for its eggs.
SEWN NESTS
The tailorbird sews two large
leaves together with grass blades.
The nest is inside the leaves.
Types and Locations
Nests are classified according to their
shape, material, and location. They vary
depending on the amount of warmth the species
needs, as well as in terms of the level of protection
they offer. The greater the pressure from predators, the
higher or better hidden a nest must be. Good examples are
isolated nests resembling high platforms; nests in deep
depressions in the soil or hidden in tree trunks, which are very safe
and provide good insulation; and nests made of clay, which are very
hard. The most typical nests resemble a cup and are found at various
locations, most often between two or three high, remote branches.
NG «
Composed:*on the habitat.
of bers; hairs’ et
feathers, ands }<27%
down,\Itinsulates 5)
the eggs-from the?)
cold-and helps
1 i inesbation “A
Structure
The cup shape is important for
preventing eggs from rolling out and
falling. Besides making the construction of
the nest easier, the use of different
materials helps make the nest sturdier, as
the smaller and more flexible pieces firm up,
the base, walls, and lining of the structure.
Different materials also provide more
efficient insulation, keeping warmth in and
cold out during the incubation and raising
of chicks. As an added reinforcement, birds
usually make the side facing the prevailing
winds thicker and the side facing the sun
thinner. Thus, the whole nest is an incubator
that conserves energy. Finally, an exterior
finish camouflages the nest among
branches, hiding it from predators.
The finish includes
moss and feathers to
smooth out the interior
and provide insulation
against the wind and
cold, which makes the
nest more suitable for
incubation.
50 THE LIVES OF BIRDS
First, the Egg
Most birds’ organs
are formed in the
first hours of
irds may have inherited their reproductive method from their ——— ass
predecessors, the theropod reptiles. In general, they lay as many , a Fa
eggs as they can care for until the chicks become independent.
Highly adapted to the environment, the eggs of the same species
have varying shapes and colors. These variations help keep them
safe from predators. They also vary greatly in size: the egg of an
ostrich is 2,000 times bigger than that of a hummingbird. e
I Birds have only one functional ovary, the left one, which grows dramatically
fLe@ during the mating season. The ovule can descend and form what are known
How It Forms @
as unfertilized eggs (the type used in cooking). If the egg is fertilized, embryonic As it feeds to grow, the
development begins. The ovule, fertilized or not, descends to the cloaca in a few embryo produces wastes that
hours or days. The eggshell begins to be formed at the isthmus, through the are kept in a special sac.
secretion of calcium. At first soft, the shell hardens when it comes in contact with
the air.
OVULES
They lie in follicles
arranged like a
bunch of grapes.
CHORION
protects and contains
the embryo and its food.
DESCENT
Once fertilized,
the ovule travels
down the oviduct
until it reaches
the isthmus. yout
YOLK SAC
ALBUMIN
SHELL
In the isthmus,
the shell SHAPE
membranes form. The egg contains an embryo in one It depends on the pressure exerted by the
side of the yolk. The yolk is held in oviduct walls. The large end emerges first.
CLOACA the middle of the white (albumin) by
It expels the egg 24 a protein cord that isolates it from
hours later on average the outside world. i
UTERUS (chicken hens). \ }
The egg becomes
pigmented, and the EMBRYO
shell hardens. PROTEIN Oval: The Conical: Spherical:
ae CORD most Prevents — Reduces the
frequent falling surface area
* = (CHALAZA)
—s
COLOR AND TEXTURE
Both texture and color help parents
locate the egg.
ry:
Dark Speckled
Egg Egg
LAYING
A group of eggs laid at one
time is called a laying. During
the mating season, a sparrow
can have several layings. If
some eggs are removed, the
sparrow can replace them
without difficulty.
BIRDS 51
AIR
SAC
SIZE
There is no exact proportion between
the size of a bird and its egg.
The bill and scales of the legs
harden toward the end, when
the chick is formed and
reaches a size similar to that
of the egg. At that point,
rotation begins so that the
chick will be positioned to
reak Its snell. 1 lb y) OZ
(500 g) (60 g)
8 Kiwi Egg Chicken Hen's Egg
When the chick is ready to break the shell, it is taking up all
the space inside the egg. The chick is cramped with its legs
against its chest. This enables it to open the shell with small
movements and with the help of a hard point at the tip of its
bill (called an egg tooth).
YOLK AND WHITE
They decrease in size.
wip
i
$,
,
t
pte
THE SHELL Pore Membrane Outer
and Inner
Membranes
Formed by a solid layer
of calcium carbonate
(calcite), it has pores
that make it possible
for the chick to breathe.
Bacteria are kept out
by two membranes that
cover the egg, one on
the inside and the other
on the outside.
thet
0) ALBUMIN
O was consumed.
THE PROPORTION YOLK
OF AN EGG disappears into the bod!
TAKEN UP BY es i
THE EGGSHELL
52 THE LIVES OF BIRDS
Birth in Detail
hen a chick is about to hatch, it starts to make itself heard from inside the egg. This
allows it to communicate with its parents. It then starts to peck at the shell with its tiny
egg tooth, which is lost after birth. Next, it turns inside the egg and opens a crack with
Adaptations for Hatching
Getting out of the egg is an intricate operation because the
space is tight, and a chick's muscles have little vigor. Birds
count on a few adaptations, such as the egg tooth and the hatching
muscle, to accomplish the task. The tooth is used for making the
first perforation, which allows air into the egg. The muscle exerts
the necessary strength, while stimulating the chicken's motor
functions to intensify the effort. Both the egg tooth and the
BIRDS 53
A GREAT EFFORT
Getting out of the shell
requires much energy from
the chick.
THE CHICK IS BORN
Once outside the chick, almost
featherless, looks for warmth
and food from its parents. In
the case of some birds that
hatch without feathers,
new perforations, at the same time pushing with its neck and legs until it manages to stick out its
head. This job demands a lot of effort and can take 30 to 40 minutes or, in the case of kiwis and
albatrosses, even three to four days. In most species, newborn chicks are blind and naked,
and they can open their bills only to receive food.
hatching muscle disappear shortly after the eggshell is broken. not all eggs hatch
simultaneously; this
benefits the firstborn
E if food is scarce.
It exerts pressure against the
shell and helps to break it.
INCUBATION
For the embryo to develop, it needs constant temperatures between
99° and 100° F (37-38° C). The parents ensure these temperatures by
sitting on the eggs and warming them with their brood patches.
DURATION BY SPECIES
The incubation period varies considerably:
between 10 and 80 days, depending on
the species.
During incubation,
some species lose
their chest feathers
and increase their
number of blood
vessels in this area.
Others pluck out
their feathers.
E TOOTH
A protuberance on the bill that
punctures the egg. Its presence
depends on the species.
ALBATROSS
PENGUIN
Both males and females
PIGEON
Females and males Lacking brood patches, the
Direct contact with incubate. They both incubate. The emperor male has parents hold the egg between
the eggs helps keep develop a brood patch. a special pouch for incubation. their feet and abdomen. ©
them warm. ; : re ; =
BROOD PATCH
SHELL MEMBRANE
Breaking the Shell
Oe EGGSHELL
This process may take from a few minutes to three or
four days, depending on the species. In general, the
parents do not intervene or help their young. When the shell is
empty, they throw it out of the nest, apparently to avoid
attracting the attention of predators. In species whose young
CRACK IN THE EGG
The chick turns inside until its
bill targets the egg's midline.
It then punctures the air
sac. With a few more
tries, it pierces the shell.
The chick then breathes
for the first time.
ASKING
FOR HELP
The chick calls for its parents
from inside. The reply encourages
it to continue the effort.
hatch with the feathers already developed, hatching is
extremely important. It has been observed that the singing of
the chicks stimulates the stragglers and delays those that have
gotten ahead; it is important that they all be ready to leave the OF THE EGG.
nest together.
SEQUENCE
OF PECKING
Between each sequence of pecking,
the chick must take long breaks.
IS THE APPROXIMATE TIME IT
TAKES A SPARROW TO COME OUT
THE CRACK EXPANDS
After making a hole in the shell,
the chick opens a crack with
successive pecks at other points.
Air gets in and dries up the
membrane, which makes the
task easier.
GETTING OUT OF THE EGG
Once the shell is open, the
chick pushes itself out with
its legs and by crawling on
its abdomen. For birds that
_ hatch without feathers, this
is more difficult, because
- ‘ they are less developed.
WHAT COMES OUT FIRST?
The head usually comes out
first, because the sharp bill
helps break the shell. Most
birds then get out of the egg by
pushing themselves out with
their legs. For wading birds and
other terrestrial birds, however,
the wings usually unfold first.
54 THE LIVES OF BIRDS
BIRDS 55
Postnatal Development
hicks develop at highly variable rates after hatching.
Some birds are born with their eyes open and with a
thick layer of down feathers. These birds can also feed
themselves. That is why they are called precocious, or
nidifugous. Ducks, rheas, ostriches, and certain beach birds can
walk and swim as soon as they are born. Other species are born
naked and develop their feathers later. They need to stay in the
nest until they have sufficiently developed, so adult birds must care
for them. These birds are called nidicolous. The most helpless chicks
are the young of songbirds and hummingbirds, because they need
warmth from their parents to grow strong. @
Nidifugous Young
Fh Nidifugous young are fully developed at the
LL moment of birth. They can move and even leave
the nest, hence their name (which means “fleeing the
nest"). This adaptation demands more incubation
time because the chick is almost fully
developed at birth. This is the case with
incubator birds (Vegapodius freycinet),
which begin their independent lives in
the outside world as soon as they
leave the shell. Ducks follow their
parents but find food on their own,
whereas chickens follow their
It is already
considered an adult.
Its flights are longer.
Its diet is composed of
97 percent vegetables;
the rest is made up of
lichens and insects.
EYE
They are born
with open eyes.
parents, and the parents show them FEATHERS
where to find food. The body emerges
from the egg
covered with damp
down. Within three
hours, it will become
dry and fluffy.
Red-Legged MOVEMENT
Partridge Within a few hours of
Alectoris rufa hatching, nidifugous
birds can run around. 1 5 d ays
It starts to perform
GROWTH short flights. It reverses
STAGES its diet, eating:
66%
seeds and
flowers.
The rest consists
of invertebrates.
30 hours
The chick keeps warm with
the down that covers its body.
SIZE COMPARISON
NIDIFUGOUS NIDICOLOUS
Tt can walk and begins to be The egg is larger, the | They lay small
fed by its parents. chick is born more eggs, with a brief
developed, and the incubation
incubation period is period, and the
longer than that of young are
nidicolous birds. helpless at birth.
66%
invertebrates.
Ours The rest consists gener Se
of seeds and
s
7 to 8 days
Growth quickens, and the first
covert feathers appear at the tip of
the wing. The bird leaves the nest.
Its diet consists of:
IS THE MINIMUM AMOUNT OF flowers.
TIME THE BLACK-HEADED DUCK
NEEDS TO BE READY TO FLY.
. e
“see e®
Nidicolous Broods
Fl Most of these chicks are born naked, with FOOD
[Lefl closed eyes and with only enough strength They need much food to An adult bird can feed its young up to
to get out of their shells. They stay in the nest. For develop. The parents must .
the first few days, they cannot even regulate their feed them 24 hours a day. AOO times a day.
own body temperature; they need their parents in
order to stay warm. Within one week, they have a
few feathers, but they require constant
care and food. They form a
numerically important group that
includes Passeriformes (songbirds).
House Sparrow
Passer domesticus
INTERIOR OF THE BILL
Its color is bright to
stimulate the parents to
regurgitate the food.
Some species have shiny
areas that can be seen
even in the dark.
12-15 days
Development is complete, and the
covert feathers are ready for
flight. All that remains is for the
EYES bird to reach adult size.
Nidicolous chicks are
born blind. They open
their eyes a few days
after birth.
FEATHERS
The chicks are
born either naked
or with down
feathers in sot
10 days
Feathers cover
everything, but they
are not yet
developed. The chick
can stay warm on its
own, and it is
voracious. Growth is
very fast.
8 days
Feathers cover the chick
almost completely, except
around its eyes. Its legs
are well developed, and
the sparrow moves
around in the nest.
STAGES OF
GROWTH
25 hours
It performs a few
instinctive movements.
It can barely raise its
head to ask for food.
12-15 days
IS THE ESTIMATED TIME THAT IT
TAKES THIS NIDICOLOUS CHICK TO
LEAVE THE NEST.
6 days
Some feathers begin to
unfold, the nails are
formed, and the wings
continue to grow with the
body. It can stand up.
4 days
The eyes open. The tips
of the first feathers
appear. It performs a
few movements.
56 THE LIVES OF BIRDS
A Diet for Flying :
as
ost birds eat assorted foods that are rich in energy renee
and proteins. Their high level of activity requires
that they eat almost constantly. Their sources of
food are varied and include seeds, fruits, nectar, leaves,
insects and other invertebrates, and meat of all kinds
(including carrion). Many species eat more than one
type of food; some even alternate according to the
seasons and to the migration cycle. This guarantees
their survival. However, there are others birds—a
minority—that consume only one type of food, for
which they have no competition. Because their
dependence on this single source of food is greater, 133
though, the risk is higher. Feeding behavior also ae
varies among different species. For example, some i
eat alone, and others eat in groups. ©
TONGUE
From Parents
to Children
Flamingos and pigeons feed their
young a special “milk” that is
produced in the crop and has a nutritional
value similar to the milk of mammals. Both
males and females produce it as soon as
food is ingested so that the chick is not
fed regurgitated food.
It is given to the
young through the
* bill. Easy to digest
and nutritious, it is
an excellent food.
\
\
A Complex System >;
Feeding on microorganisms that live in salty water demands a complex filtration system.
The flamingo's bill is specially suited to this task. Its tongue and throat pump the water
inside the bill as they ascend and descend, bringing water through the hornlike lamellae, which
resemble whale baleen, to retain the food passing through them. Their tongues also have a depressed
area, where the stones and sediments that come in with the water collect. The whole operation requires
that the flamingo submerge its bill upside down. Because of the number of microorganisms they need to
consume and the time it takes to filter them, flamingos usually spend many hours in the water. The risks
involved in this activity are mitigated by the fact that flamingos do not eat alone, but rather in groups.
Occasionally, there are instances of aggression, possibly because of territorial conflicts.
A second filtration occurs
inside the bill, as the
water is expelled. The
lamellae (small plates)
catch the microorganisms
Filtration
of Food
as wage fie but let water and other
submerges its bill in
the briny water to feed VAS ES,
on the microorganisms
living there.
Cross-Section
of the Bill
The flamingo fills its bill
with water by raising
its tongue. By doing
this, the flamingo
performs an initial
filtration that keeps out
undesired substances.
LOWER
MANDIBLE
Tongue
Lamellae
UPPER i,
MANDIBLE i
nid
Hooks to Hold
the Bill
WATER IN MOTION
BIRDS 57
Types of Diet
Birds expend a great deal of energy, and their
diet must be suited to their high metabolic
rates. They eat practically anything, although the diet
of some birds is very specific. The same foods are
not always available, which causes most birds to
adjust their diets throughout the year.
1.
The flamingo produces
milk in its crop only
when it is not eating. A
protein called prolactin
participates in its
preparation, just as
with mammals.
NECTAR
is a solution of sugar and water that flowers
produce. It is very high in energy and easy to
digest. In order to get it, a bird must have a
long, sharp bill. In temperate regions, nectar
is plentiful in the spring and summer, whereas
in the tropical regions, it is available year
/ round. Hummingbirds and honeycreepers are
very fond of this juice.
3.
This milk has high
concentrations of the
pigment that colors
the feathers; that
is why the bird's
color changes to
the characteristic
pink while
molting in
adolescence.
SEEDS AND GRAINS
The high energy and protein
content of seeds make them an
ideal food for birds. The problem
is that they are seasonal.
FISH
The abundance of fish
throughout the year makes them
one of the favorite foods of
marine birds. They have a high
nutritional value.
FRUIT
In the tropics, this diet is very
common because fruits are available
throughout the year. In temperate
and cold regions, fruit can be found
only in the summer. Fruit has a high
energy value, and many birds eat it.
Strategies
Depending on the abundance
of resources, the needs of the
species, and the strategies for
getting food, birds may eat alone or
in groups. If food is scarce or widely
scattered throughout a region, birds
eat alone and defend their territory.
On the other hand, if food is
abundant, they prefer to eat within
the safe confines of the group.
SOLITARY
Usually birds of prey, such as
eagles and owls, hunt alone
because food is scarce and is
randomly distributed. Hunting
alone has a drawback in that
birds must also watch out for
predators, which takes time
away from hunting.
THE HUMMINGBIRD'S TONGUE
Long channeled or tubular
tongues suck the nectar and catch
insects at the bottom of the
corolla of a flower.
Pointed tips, in the
shape of brushes
MEAT
Hunting and scavenging birds
feed on meat. They rarely
specialize in one type of prey,
but the prey's size determines
its selection.
LEAVES AND PLANTS
Few birds feed on leaves because
they have low energy value. Birds
that do have undergone
adaptations that permit them to
digest cellulose.
INSECTIVORES
Insects are rich in energy and
proteins, and they are highly
abundant. Thus, many bird species
eat them. In cold regions, they can
be found only in the summer.
TOGETHER
This behavior is typical of
ocean birds, such as pelicans
and seagulls, and of aquatic
birds, such as flamingos.
When birds eat in groups,
each group member can warn
the others about possible
dangers, which is beneficial.
58 THE LIVES OF BIRDS BIRDS 59
I |
i |
Migration Routes...) ss" ven sr —
= — aa, Oenanthe oenanthe
: Sex De
al = 24 a ti
Cape Gannet
Morus capensis
Snow Bunting
Plectrophenax nivalis
RUBY-THROATED
HUMMINGBIRD
Archilochus colubris : 7
Peregrine > 5OO miles ie? gor A Barn Swallow
Falcon 4° > (800 k » Lesser S| a Hirundo rustica
Falco - m) \ ff jay 1 ’ Aquila p
peregrinus Gulf Of om «> : THE DISTANCE THEY FLY ig } ; rm PA ae
Mexico” eens NONSTOP ACROSS THE wa" . j % Pacific
—" “th GULF OF MEXICO. THEY DO : ie % Ocean
% IT IN JUST 20 HOURS. . — J : f 7 %,
= a se . are : MEETING POINT “% i)
‘ ~ of , 4 ° ‘*
Pacific Atlantic we y a ‘ . 7 ri ty
a ia 1 billion
4 BIRDS MEET IN THE DEAD
Behavior
SEA VALLEY EVERY YEAR Bar-Headed Goose
FL In order to survive, millions of birds 2 WHERE THE ASIAN, Anser indicus
Lf from all over the world start a journey EUROPEAN, AND AFRICAN
every fall in search of better climates. The MIGRATION ROUTES
instinct of migrating, which other animals share CONVERGE.
with birds, was acquired after a long
evolutionary process. Some birds fly thousands of
miles through mountain ranges; others follow the
course of a river without stopping until they reach
their destination; others land after a short trip. In
general, birds undergo physiological changes that are
related to the length of their journey; some even lose almost half
their weight during the migration. Routes tend to be fixed,
although some migratory birds do not always follow them exactly.
The colors on the map indicate the most important routes. There are
collective and individual migrations, and birds may travel during the
day or at night. It is surprising how fast birds travel. Many studies
have recorded that carrier pigeons and white-headed sparrows can
cover more than 600 miles (1,000 km) in a day. Shorebirds, such as
godwits and curlews, are among the birds that cover the most
distance. They are also among the birds most faithful to routes.
Barn Swallow
Hirundo rustica
~
American Golden Plover White Stork N ASIA FLYWi
Pluvialis dominica Ciconia ciconia \ H Ow Th ey Fi n d Th ej r
Way Around Azimuthal Angle:
Sun/Trajectory
=. Indian
- Ocean
Curlew Sandpiper
Calidris ferruginea
we Birds use a compass-and-triangulation
caspian Tern (La system that lets them know where they are xt
5 é Ste ie
Types of Migration ree according to the position of the sun or stars. This
The north-south path traveled by ARCTIC TERN system is similar to the one used by seafarers. It
many species is called latitudinal Sterna paradisaea 7 consists of measuring the sun's angle of inclination , \4
migration. A second pattern,
which occurs in an east-west
direction, is called longitudinal
migration. The last pattern is
called altitudinal migration; it is
performed by birds that move up
and down mountains seasonally.
in relation to the horizon (azimuthal angle) and South ef : 4
s 20, OOO ] | | l il es comparing it to the angle the bird knows through Southwest ot
— a) its biological clock. Birds also orient themselves | :
Lori ttc ae (40, 000 km)~ by using the Earth's magnetic field. Furthermore, >
IS THE ae IT CAN COVER ON those migrating during the day register landmarks ; :
Antarctic Ocean ITS ROUND-TRIP MIGRATION P on their routes, such as mountains, lakes, or
BETWEEN THE POLES. IT IS THE Wandering Albatross deserts. Still others follow older birds or are Northeast
ANTARCTIC FLYWAY LONGEST MIGRATION IN THE WORLD. Diomedea exulans guided by their sense of smell. North
-
Flight Direction:
Northeast to Southwest est
a |
-
60 THE LIVES OF BIRDS
Defense’ Strategies
irds have many ) = including cats, snakes, crocodiles, and other birds. To
— @ " BIRDS 61
Defense of the Brood
> Hatching and youth are times of
critical vulnerability for birds. During *
these phases, they are forced to keep still
because they are easy prey. For this reason,
parents permanently watch over their nests,
even attacking strangers if they get too close.
-. FEIGNING INJURY
A very widespread behavior is to pretend to be
wounded or sick. This allows a bird to avoid being
defend themselves inst these predators, birds use various strategies, the most
common of which is camouflage. Some birds blend in with their surroundings
and thus go unnoticed by their enemies. Chaparrel birds, whose plumage colors and
+
chosen as prey. This behavior is common among
that keep still in the presence of unknown animals, feigning death, i 0 Pineons.
whereas others face an enemy and fight. It is not uncommon to see
magpies, thrushes, and other birds chasing away strangers that get
close to their nests.» P
’ % ’ ATTACK PROTECTION
_ In other situations, birds adopt openly aggressive When a parent detects danger, it gets close to its
7 behaviors in the presence of intruders or predators. young and covers them so that they are not alone.
Magpies can even hound and chase away eagles if the This behavior is common among tropical birds
e latter threaten their brood. Such active defenses are (tropical seabirds). Several species of curlews and
*
- s %
Individual 4
iy Among solitary birds, it is co t :
flee quickly if a stranger is present. 4
all solitary birds react this way, though; some
have developed specific techniques to defend
more common among birds of prey. sandpipers place their young betwee: legs,
whel a carry their chi jacks
Collective Strategies
themselves.
: ay aie Birds that have group behaviors usually
‘ 7 develop group strategies to protect
ESCAPE themselves against predators. Being numerous is a
In the presence of terrestrial predators, a bird's first
reaction is to take flight. If the bird cannot fly, it lo k
for shelter or a hiding place.
_ guarantee that the species will go on. They also
adopt other tactics as a group.
COLONIES
A great number of birds can defend themselves better from
predators when in groups. For that reason they even form
colonies with other bird species when raising their young:
on™
Ae
WN
N
iy
dense formation. If they are near a tree, they do not hesitate to hide in it.
Wee - FLOCK . :
"e In the presence of predators, birds form flocks that a
. synchronized manner, which makes it hard for the _ '
EXPANSION . ® predators to focus on any one individual. o
Owls spread out their wings to look bigger than
they really are. > A ’ ATTACKS AND COLLECTIVE
. . : i.
Many birds that live in groups have developed several
‘ .. . e “ he ' hounding behaviors in the presence of potential enemies.
; , \\\ ” y They perform them to help an individual that is in danger
Q\ AN P . or a to flee.
L \\ ZZ» ; WARNING
: a ; . They emit callings that warn the whole colony. The great
majority of species have a specific and characteristic cry
- that is usually simple, brief, and very audible.
rer, fe a their excreriaag inthe face «(i . They often agi these warnings while guapting postures
birds that prey on them. This distracts the predator (such as stretching the neck or shaking the wings) that
and makes it possible to escape. v a alone are enough to warn other individuals of the
intruder's presence.
te — Ee
CAMOUFLAGE 7 > :
is Very common and is one of the most efficient defensive strategies: "
Many birds develop plumage to imitate the dominant colors and e : > = :
shapes of the environment where they live. When they notice the al
presence of a potential enemy, they stay motionless to avoid calling ad 3 Bors
attention to themselves. There are a few notable cases, such as that = eo <
of the tawny frogmouth (Podargus strigoides), pictured above. May
partridges and terrestrial birds are experts at the art of blending i
with the landscape; the rock ptarmigansfor example, has white >
plumage in the winter that becomes terra-cotta in the summer.
= — vs. = a eee
*? G » = as
Diversity and Distribution
he environment in which an
organism usually lives is called
its habitat. In their habitats,
birds find food, the best places
to build nests, and escape
routes in case of danger. An almost
universal pattern of distribution shows
that more species live in the tropics than
elsewhere. With evolution, birds with a
common origin have diversified as they
have begun to occupy different
environments. This phenomenon is
called adaptive radiation. We find ocean
birds, which have undergone many
changes in order to live near the sea, as
ONE BIRD, ONE NAME FRESHWATER BIRDS
WHERE THEY LIVE ARMED TO HUNT
NO FLYING ALLOWED TALKATIVE AND COLORFUL
MARINE RESIDENTS THE PERCHERS CLUB
well as birds that live in freshwater
environments, in forests, and so on.
Each type has acquired special physical
traits and behaviors as a result of the
adaptive process.
64 DIVERSITY AND DISTRIBUTION BIRDS 65
One Bird, One Name
o learn more about different birds, we give each species a name.
Ancient peoples grouped birds according to practical traits and
mystical beliefs. They used birds as food or considered them to be
bad omens or symbols of good luck. The people who developed
scientific thought created a classification system that took into
consideration the external form as well as the behavior of these
vertebrates; hence, the denominations predator, wading bird,
and songbird were developed, among others. The most recent
system of classification, which is based on genetic and
j
Diversity and the Environment
Living birds are distributed among a wide variety of habitats. They can be found | , Avs Wea a .
in aquatic (freshwater or marine) and aero-terrestrial environments. Marine birds
live on cliffs, on islands, or in mangrove swamps. They are excellent fishers, and they use
seashores or crannies between rocks as refuges for nesting. In freshwater bodies, such 4
as rivers and streams, ducks feed on plants and surface microorganisms. Muddy shores : se
are rich in insects and mollusks, which are the favorite dishes of ibis. Herons, storks, and
egrets spear fish with their sharp bills as they wade in water with their long legs
without getting wet. Forests, jungles, mountain ranges, and wide plains form most of
the world's aero-terrestrial environments. In jungles and forests, predatory birds hunt
their prey, while trogons and parrots gorge on insects and fruit. Rocky peaks are the
refuge of condors, which fly for hours in search of the remains of dead animals.
Ostriches run over prairies and savannas.
r] i ot ‘ Eagles, V ures,
/ and Falcons
COLIIFORMES
6 SPECIES
H Mousebirds
(ans
_ PSITTACIFORMES
360 SPECIES
ie
CUCULIFORMES
F A ; ‘ ‘ _ Parrots, Parakeets,
evolutionary criteria, has generated a hierarchical Opisthocomus hoazin ee nieces eae beries acletiog
izati f th ti ta tl b i d t d is a tropical bird species that inhabits the ple AU eee lA and Macaws
organization of names that IS constantly being updated. 317 SPECIES :
Amazon. The presence of talons on the
chicks' heels links them to their earliest
ancestors, including Archaeopteryx.
Pigeons and Doves
PICIFORMES
382 SPECIES
. . Woodpeckers,
What Is a Classification? PHYLUM CLASS FAMILY GENUS SPECIES : Tene oe
Since the early Renaissance in the 16th - Hirundo ristica 7
century, scientific classifications assigned - — Hirundo (barn swallow) 1
compound names to birds, as well as to other Hirundinidae b se
living creatures. The first part stands for a genus a
and the second for a specific name. Thus, the
rock (domestic) pigeon is called Columba livia in Viren oltvoceus ro prong \
scientific terms. The discovery of new species in Vireo (red-eyed vireo) Hummingbird ‘ r
: . ae gbirds
different parts of the world widened the array of Vireonidae and Swifts é CHARADRIIFORMES
birds so that compound names were no longer 350 SPECIES UPUPIFORMES
enough. The level of family was established to t Seagulls, Lapwings, 1 SPECIES
group genera of birds that share similar traits. In "me alr and Plovers Haanae
turn, bird families that share common traits —— P
were grouped into orders. These were then Chordata Aves di ae
combined into a category called class. Classes Torus Larus atricilla a
include all current and extinct birds. Birds share (laughing gull) —_
a higher category in the hierarchy-the phylum- Laridae J a» STRIGIFORMES 7.
with fish, amphibians, reptiles, mammals, and qv as S TROCGONIFORMES
vertebrates in general. & 39 SPECIES
: st Trogons and
ef CICONIIFORMES E e Quetzals
CAPRIMULGIFORMES , 120 SPECIES 190 SPECIES =
109 SPECIES Herons, Storks, Moorheiis, (e anes 5
Potoos, Frogmouths, Ibises, and Egrets t a
and Nightjars . Fa
- >< =
- SPHENISCIFORMES ‘ pe, =
a 18 SPECIES G72 “a
y Penguins WT df \
i ‘be ‘
| \ GAVIIFORMES PROCELLARIIFORMES PODICIPEDIFORMES ANSERIFORMES PELECANIFORMES en ae N
\ 5 SPECIES 110 SPECIES 21 SPECIES 150 SPECIES 62 SPECIES | | mailin \
f Loons (diving birds) Albatrosses, Petrels, Grebes Ducks, Geese, Pelicans, Boobies, | b 7
and Fulmars and Swans and Cormorants y. } Ah
A FCoe Es IDILOEE
y 1 SPECIES)
Flamingos |
urkeys, Quails,
asa cats Ss, and Pate
BIRDS 67
66 DIVERSITY AND DISTRIBUTION
Where They Live
NUMBER OF
Biodiversity in the World Spores
Fh The most diverse regions in terms of bird “> upto 200
ith their mobility, birds have conquered all areas of the Earth. Despite this Heal) popultions are the woples Betaise of the lesan
hes ‘ i" : s sige favorable conditions of abundant food and warm @ 400 - 600
characteristic, there are few cosmopolitan species—that is, most birds have specific climate found in them. Temperate regions, however, @ 600-800
habitats determined by climate and geographic features. Count de Buffon in the 18th Many MIGIF Ses Oni are sleet inatare: TOPrTagta tng 200; 00
‘ : n- 7 7 . birds from tropical and polar regions. Cold regions, @ 1000 - 1200
century was the first person to notice that living beings are not distributed homogeneously. By on the other hand, have little diversity but are rich in @ 1200 - 1400
population density. The rule is that diversity of life- @ 1400 - 1600
analyzing how animals were dispersed on the planet, he realized that different places had
forms happens in places where the environment @ 1600 - 1800
different types of fauna. After the work of naturalist Charles
Darwin and ornithologist Philip Sclater, it
became clear that organisms are
situated in specific
biogeographic regions. @
ASIA COUNTRIES WITH THE
7 MOST SPECIES
Palearctic
) - More than 1,500
PAINS a Species 9%
fd NORTH ; 73 families Because of similar climatic conditions, Colombia
} \) Fratercula artica , i
Nearctic “AMERICA a q many authors merge the Palearctic and Brazil
" EUROPA CHARACTERISTICS Neoarctic regions, calling the combined Peru
Species = 4 Climatic barrier of cold weather region Holarctica. Ecuador
P ise iis 7 and oceanic isolation Indonesia
62 Families ; :
E Low diversity of species More than 1,000
CHARACTERISTICS Oceania Most are migratory species Bolivia
Climatic barrier of cold weather S ~ Many. insectivorous and aquatic birds Venezuela
and oceanic isolation es l pecies 2% China
Most migrating species i : 5 a 15 Families ve Endemic Avifauna: wood grouse, India
Many insectivorous and aquatic birds CHARACTERISTICS waxwings, flycatchers, cranes f . Mexico
Affinity with Palearctic Esigcaresiana nierienokelinaics AFRICA rs Democratic Republic
ee ‘ of the Congo
-Aasnieavit aes Pacific CENTRAL Gliders, divers, and swimmers Pe
ndemic Avifauna: loons and puffins @ y
p Ocean AMERICA Abundance of fish-eating species \ > Kenya
Many cosmopolitan species Pare 4 Argentina
] ndian
ag Seat aoa to Neotropic Genie _ Afrotropic i peek a
@ Environmen i sheathbills, petrels, penguins, a ie te! oe
Species and seagulls Species 19% 2 a
F™@ Birds are found in all habitats of the world, although 86 Families 73 families Indomalaya
Le most live in tropical regions. Their ability to adapt, ) y) “
eaniet purge 2 Be to ee CHARACTERISTICS. 32% CHARACTERISTICS © & l / } Species 16 %
Pear ee eee ey ieee ce aaicne Soatian eee Long-lasting geographic Maritime and desert isolation 66 families
succeeded in acclimating themselves. They have undergone a isolation : 9
highly varied array of changes in form and behavior. Emperor = e Great number of Passeriformes CHARACTERISTICS
penguins not only nest in Antarctica but they also incubate Many primitive species Many flightless birds ——= : Vv
their eggs between their feet for 62 to 66 days. Great numbers of frugivores Affinities with the Afrotropical zone
The male Lichtenstein's sandgrouse has Endemic Avifauna: ostriches, Tropical birds
developed a sponge of feathers to bring Endemic Avifauna: rheas, SOUTH turacos, cuckoos Many frugivores
water to its chicks, and tinamous, oilbirds, hoatzins, AMERIGA
hummingbirds have special cotingas, and stripe-backed Endemic Avifauna: ioras, pittas, swifts
wings that enable them to antbirds OCEANIA
a at This region undoubtedly has the greatest Australasia
: diversity of birds. The variety in the South
American tropics, the most important l 59 Species 15%
tropical zone in the world, is one and a 9 64 families
half times greater than that of tropical barge di ng lnalhtl i teastaorti A
Africa. With more than 1,700 species, SO le CHARACTERISTICS
Colombia, Brazil, and Peru are the
countries with the greatest diversity of
avifauna. Even Ecuador, a much smaller
country, has more than 1,500 species.
HOATZIN
Opisthocomus hoazin
requires less severe adaptations.
OSTRICH
Struthio camelus
Long isolation
Many flightless and
primitive birds
Endemic Avifauna: emus, kiwis,
cockatoos, birds of paradise
68 DIVERSITY AND DISTRIBUTION
No Flying Allowed
few birds have lost their ability to fly. Their main
characteristic is wing loss or reduction, although for some
4 ~*~
Such birds weigh more than 39 pounds (18 kg). This is the
case with runners (ostriches, cassowaries, emus, rheas,
kiwis), extremely fast birds that live in remote
areas of New Zealand, and swimmers, such as
penguins, that have developed extraordinary
aquatic abilities.
Super Swimmers
Penguins’ bodies are covered with three layers of small, overlapping feathers. A penguin
has small limbs and a hydrodynamic shape that helps it swim with agility and speed.
Dense, waterproof plumage and a layer of fat insulate the bird from the low temperatures of
the regions where it lives. Since its bones are rigid and compact, it is able to submerge itself
easily. This adaptation distinguishes it from flying birds, whose bones are light and hollow.
FLIPPERS
The short, compact wings look
like flippers. They are essential
to the penguin's underwater
movements.
Rockhopper
Penguin
Eudyptes crestatus
HUNTING
The wings work like
flippers. The foot—with
four joined toes pointing
BREATHING RELAXING
When looking for food, When resting in the
penguins need to leave the + water, they move slowly.
water and take a breath They float on the surface
backward—and the tail between plunges. with their heads up and
steer the direction of balance their bodies with
the dive. their wings and feet.
a remarkable size may be the cause of their inability to fly.
ATROPHIED
WINGS
|
The Ratites
Running birds belong to 59 ft
the group of the ratites (L8 m)
(rata = raft, an allusion to the
flat sternum). The front limbs
either are.atrophied or have
functions unrelated to flying.
The hind limbs have very
strong muscles as well as
sturdy, vigorous bones.
Another difference is found in
the sternum. It is a flat bone
without a keel, which flying \ :
and swimming birds possess.
A single species inhabits
eastern and southern Africa.
Adults reach a height of 9
feet (2.75 m) and a weight of
330 pounds (150 kg).
in-the Southern Hemisphere.
The Tinamidae, native to
Central and South America,
belong to this group
(partridges).
*poundls (150 kg).
Running and Kicking
Ostriches usually run to escape from predators
or to hunt small lizards and rodents. In both
cases, because of their strong legs, they are able to
reach a speed of 45 miles per hour (72 km/h) and to
maintain it for 20 minutes. When running is not
enough to protect the bird, kicking is a valid recourse
that discourages the attacker. In courtship displays,
forceful stamping is also used to win over females.
PELVIS
STRUTHIONIFORMES
The ostrich is the only
species in this group. It uses
its wings for balance when.
running fast. It has only two
Wild ratites can be found only é toes on each foot. The adult
. male can weigh up to 330
RHEIFORMES
Rhea are common.in South
American countries, such as
Argentina. They look like
ostriches but are smaller.
< “Their three-toed
then to 7
neck a
make the
BIRDS 69
CASUARIIFORMES BMIES
Agile runners and 2
swimmers. The colors on
their necks and heads are fur
_ distinctive. A bony hoof
Us have four
bt, and their
protect m
In many cases, running birds can be found in
many parts of the world because of human
intervention. The area where flightless birds
have diversified the most is Oceania, due to
continental isolation.
Der ee ep oe
“
; tis
az :
A
IBIS (Ibis sp.): Some filtrate, STORK (Ciconia sp.): It
and others fish. fishes with its long bill.
aA
“»
ma |
White Ibis
Edocimus albus
A DUCK'S DIET -
HOW THEY USE THEIR FEET TO SWIM
A duck moves its feetyinytwo ways. To advanci
uses its webbed feet to. row. It closes the toe:
SHOEBILL (Balae-niceps rex):
It eats among floating sedges.
THE LEGS OF AN IBIS
keep the bird above the
water but close enough to
It swims on the surface, It sticks its head into the It floats face-down
looking for food water, abruptly pushes ip ake the bottom * fish. Ibis also stir up the
underneath the water. back its feet, and turns its h its bill. ' 4 beds of lakes and ponds.
neck downward. Pails - ; HERON (Egretta sp.): It COMMON SPOONBILL HAMMERKOP (Scopus
- r , fishes with its sharp bill. (Platalea leucorodia): It eats umbretta): It fishes and
fone i v " several types of aquatic animals. hunts small animals.
a. cf
#
:
A
os
74 DIVERSITY AND DISTRIBUTION
Armed to Hunt
irds of prey are hunters and are carnivorous by nature.
They are perfectly equipped to eat living animals. Their
eyesight is three times sharper than that of human beings; their
ears are designed to determine the precise status of their prey; they
have strong, sharp talons; and they can kill a small mammal with the
pressure of their talons alone. Their hook-shaped bills can kill prey by =
tearing its neck with a single peck. Eagles, falcons, vultures, and owls A vuneited
are examples of birds of prey. Birds of prey can be diurnal or nocturnal, “ p maint on cane leslie
and they are always on the lookout. © ; a Nae
Diurnal and Nocturnal
Eagles, falcons, and vultures are
diurnal birds of prey, whereas owls
are nocturnal—that is, they are active
during the night. These two groups are not
closely related. These birds' main prey
includes small mammals, reptiles, and
insects. Once they locate the victim, they
glide toward it. Nocturnal birds of prey are
specially adapted: their eyesight is highly
developed, their eyes are oriented forward,
and their hearing is sharp. The feathers on
their wings are arranged in such a way that
they make no noise when the bird is flying. can determine the location of degrees and a bifocal vision Red-Backed Hawk
In order to protect themselves while prey with great precision. of 50 degrees. BRO AEE,
sleeping during the day, they have dull
plumage, which helps them blend in with ——
their surroundings. CERE
Fleshy formation, | —________|
Bills
The bills of birds of prey are hook-
shaped. Some birds of prey have a
tooth that works like a knife, allowing
them to kill their prey, tear its skin and
muscle tissues, and get to the food easily.
The structure and shape of the bills of birds
of prey changes depending on the species.
somewhat thick
and
Scavengers (for example, vultures and condors)
have weaker bills because the tissues of
animals in decomposition are softer. Other
species, such as falcons, catch prey with their
talons and use their bills to finish it off with a
violent stab to the neck, breaking its spine.
BALD EAGLE
Its hook-shaped bill is
common to many birds
of prey.
SPARROW HAWK FALCON GOSHAWK The study of pellets makes (8 km)
Its thin bill enables it to It can break the spine Its strong bill can catch it possible to determine IS THE DISTANCE FROM GRIFFON VULTURE FISHING EAGLE rn GOSHAWK SPARROW HAWK
take snails out of their of its prey with its prey as large as hares. the fauna of small areas WHICH A FALCON CAN Its long toes do not have Tts toes have rough scales that look It has calluses at the tips of Its feet have tarsi and short,
shells. upper bill. with great precision. PERCEIVE A PIGEON. a good grasp. like thorns, which help it to eatch fish. _its toes. strong toes.
EURASIAN EAGLE OWL BALD EAGLE
Bubo bubo Haliaeetus leucocephalus
Its ears are asymmetrical and Tt has a visual field of 220
BIRDS 75
HOW THE VULTURE HUNTS DIMENSIONS
The wings of birds of prey are
adapted to suit their flying
requirements. They can measure
up to 10 feet (3 m).
a ee
| |
(itl to 9.5 ft (095-29 m).
eee eal
| |
= 45 to 8 ft (135-245 m) -
7
Thanks to their
*
n thermals,
vultures can find
tarcasseson s—sknOwiift
he able to
Eoaiett | mr ye
. again a - ep: “ea
- a ~ , see1c 94 to 5 ft (2-15 m)
e~—_\>-*
‘ 4
: \ 2.6 to 6.4 ft (0.8-195 m)
soft 2.2. to 4.1 ft (0.67-1.25 m)
NOSTRIL
Olfactory
TIP canals
Where the
tooth is
located
that the bird uses as pincers to catch its
prey in flight. The osprey also has thorns on the
soles of its feet, which help it to catch fish.
Zone-Tailed Hawk
Buteo albonotatus
OWL PELLETS
Owls produce pellets. They
swallow their prey whole
and regurgitate the
indigestible substances.
SA
yt - a
76 DIVERSITY AND DISTRIBUTION
Talkative and Colorful
arrots form a very attractive bird group with a great capacity for learning. This group
LP comprises cockatoos, macaws, and parakeets. They share physical characteristics, such as a
big head, a short neck, a strong hook-shaped bill, and climbing feet. They have plumage in
many colors. Toucans and woodpeckers share with parrots the colors of their feathers and their
type of feet. Toucans have a wider, thicker bill, but it is light. Woodpeckers are climb
a strong, straight bill, a tail of stiff feathers, and a distinctive crest. They form num
and most nest in trees. — oe
Eating, Climbing,
and Chattering
Parrots use their bills to feed and to
move about tree branches; they use
their bills as an extension of their feet to give
them support when they climb. Parrots also
have a curved profile, a pointed tip on their
upper mandible, and sharp edges on their
Th dap
ability to imitate the human voice has made on
them very popular. However, they are far » UPPER PART OF HOOK
from being able to produce language. In , Sharp projection
reality, they are merely good imitators: they used to open seeds
use their excellent memory to imitate sounds. pressure is exerted
They do this when they are hungry or when and fruits are torn
they detect the presence of unknown people. Open.
UPPER AND LOWER MANDIBLES
The hook-shaped bill is flexible; the mandibles are
joined to the skull by hinges. At its base, the upper
mandible has a fleshy protuberance called a cere.
It is where the most
WOODPECKERS
hollow out tree trunks with pecks in
order to build a nest and to feed on
insects that eat wood.
TOUCANS
Their big bills have
serrated edges that
suit their diet of fruit.
They live in the South
American jungles.
. -%
- | THE HABITAT OF
we WOODPECKERS
XS They live in the woods and
EAN yy can often be heard
— yi :
~*
\ \
ts \ .\ there. Their
, t i" adaptations to —
arboreal life are
demonstrated by their strong,
4) thick bills and their stiff tails, which
they use for support, together with
their feet. They use their hearing to
locate tree-boring insects; they then
peck the wood incessantly until they
find them.
Q ALS =
They belong to the family
Trogonidae. They have feet
adapted to arboreal life.
Males have brilliant
plumage and long,
attractive tails.
COCKATOO
HYACINTH
_
WINGS
Usually they are \
short and rounded,
suitable for flying
among branches.
FEET
In som > =
They use it ta |
with their bi
y a a
FEATHERS AND COLORS
They have toug} lustrous plumag 1
abundan en feathers helps them to
c leaves. In we America
ues of blue,
hide amo
the array of colors include
yellow, and red.
HOOKED BILL
78 DIVERSITY AND DISTRIBUTION
The Perchers Club
asserines—or Passeriformes, the scientific name—form the widest and most diverse order
What distinguishes them? Their feet are suited for perching and, therefore, for living among tr
although they can also stroll on the ground and through the brush. They inhabit terrestrial —
environments all over the world, from deserts to groves. Their complex sounds and songs originate from «
very well-developed syrinx. Their chicks are nidicolous—that is, naked and blind at birth. In their youth,
they are agile and vivacious, with very attractive, abundant, and colorful plumage. —
THE SMALLEST
Passerines are small in comparison with other birds. Their size
varies from 2 inches (5 cm) (bee hummingbirds, Mellisuga
helenae) to 7 inches (19 cm) (Chilean swallow, Tachycineta
leucopyga) to 26 inches (65 cm) (common raven, Corvus corax).
RAVENS 26 in (65 cm)
They eat everything:
fruits, insects, reptiles,
small mammals, and birds.
They are skillful robbers of
all kinds of food.
HUMMINGBIRDS 2 in (5 cm) SWALLOWS 7 in (19 c
They get so much energy from Swallows have great
nectar that they can double agility and skill. These
their body weight by eating. popular migratory birds
However, they use this energy have bodies suited for
up during their frantic flights. long trips.
Family Album
Four basic groups have been established to facilitate
the study of families: passerines with wide bills;
ovenbirds, whose plumage is dull and brown (ovenbirds are
noted for the great care they take in building nests);
lyrebirds, whose tails have two external feathers that are
longer than the others; and songbirds, with their elaborate
and pleasant singing. Songbirds form the most numerous and
varied group; it includes swallows, goldfinches, canaries,
vireos, and ravens.
PASSERIFORMES BIRDS
Passerines have been classified into
79 families, with more than 5,400
different species.
D0 %
THE PERCENTAGE
OF BIRDS THAT
ARE INCLUDED IN
THE ORDER
PASSERIFORMES
~LYREBIRDS
There are only two species
of these Passeriformes,
and they are found only in
Australia. They are very
melodic and are excellent
imitators of other birds.
They can even imitate the
sound of inanimate objects,
such as horses’ hooves.
PERCHING FOOT
Three toes project
forward, and the
well-developed hallux
projects backward.
This type of foot
allows the bird to hold
on tightly to branches. 4
WIDE BILLS
They are native to Africa
and Asia and inhabit tropical
zones with dense vegetation.
They eat insects and fruits.
They produce nonvocal
sounds with the flapping of
their wings. They do this
during courtship, and the
sound can be heard 200 feet
(60 m) away.
“They: range from one hemisphere to the Oe:
“other, They raise their chicks in the
north and fly to the south to spend
winter there. They fly all the way to
Tierra del Fuego. Their sense of
direction is remarkable. They can find
and reuse their nests after returning
from a migration.
gener.
birds
perfo
BARN SWALLOW
(Hirundo rustica) (22.0
Barn swallows spend most
of their time traveling to
temperate zones. State
south,
and South America. The barn
swallow travels 14,000 miles
Bronchial
— Muscles
Bronchial
Ring
In the summer, during the
reproductive season, they
live in the Northern Hemisphere
on the American continent. In
al, neotropical migratory
are those that reproduce
above the Tropic of Cancer.
When winter arrives in the
Northern Hemisphere, they
rm a mass migration to the
occupying the Caribbean
,000 km) during its
migratory trip from the United
Ss to southern Argentina.
OVENBIRDS AND
THEIR RELATIVES
Their nests are
completely covered
structures, similar to
ovens. Other members of
this family build nests
with leaves and straw,
weaving interesting
baskets. Still others dig
tunnels in the ground.
ROBIN CHICKS (Erithacus rubecula) 82-83 88-89
Although their natural habitats are
humid groves, they usually seek 84-85 90-91
shelter in cities, always close to water.
86-87
82 HUMANS AND BIRDS
Rites and Beliefs
Birds have long enjoyed a prominent place in religion—first as totems and then as
iconic representations of gods. Many religions have featured deities with the wings or
heads of birds. Birds were also celestial messengers, and the future was interpreted through
their flights. The crow was Apollo's messenger in ancient Greece; the Maya and Aztecs had
Quetzalcéatl, their supreme god, who was named after the quetzal (a brightly colored Central
American bird); and the Egyptians represented their fundamental god Horus with a falcon.
FENGHUANG QUETZAL GARUDA FRESCO
was the messenger bird of Pictured above is a detail of a Pictured above is a :
Xi Wangmu, goddess of Mayan ceramic piece featuring winged deity, featured on a ’
fertility and eternity in quetzals, Mesoamerican birds fragment of a mural from
ancient China. A detail of a with long green tails, from which, the Hindu temple of
painting in the caves of according to myth, the god Garuda, in Ananta ~
Mogao, Dunhuang, China, Quetzalcéatl took his clothing and Samarkhom, es
is pictured above. name: “feathered serpent.” Bangkok, Thailand.”
¥
Bird Symbolism
Throughout history and across cultures, human
beings have used birds to symbolize several
concepts. The fascination that their flight creates was
source of inspiration for such interpretations. Tod
strongest and most widespread association is the
flight of birds with freedom. In distant times (and
distant times), however, birds have represented ma
things, from fertility and happiness, with their sprin
to deep mourning, in the case of crows and vult
Wisdom has been associated with owls, and shi
with crows. According to a certain modern tal e, sto
responsible for bringing babies, and eggs are the un
symbol of gestation. Pa aid
EAGLE
In Greek mythology, it was the
symbol of Zeus. The Romans used
it on their legions’ banners. For
many native North American
cultures, it represented war, and it
was the emblem of feudal lords
and emperors. Today it is the
national symbol of Mexico and the
United States.
DOVE
S} Doves currently stand for peace, but
in ancient Greece, Syria, and
Phoenicia, they were used as oracles.
In Mesopotamia and Babylon, they
embodied fertility. For Christians,
they symbolize the Holy Spirit and
the Virgin Mary.
Birds and Human Culture
irds fly, sing, dance, and have showy plumage. Because of these qualities,
they have fascinated human beings throughout history. Some species, such
as eagles, have played an important role in world literature because of
their aggressiveness and beauty. Some birds have also been assigned symbolic
meanings: doves, which currently represent peace, are one example. Human
beings have also been able to make use of birds. In the past, they were often
used by sailors to find land, and in other cases they were trained to hunt. e
-
'
Falconry
This practice originated in
Asia, in the homeland of the
nomadic Mongols—descendants of
Genghis Khan—where, to this day, it is commonly
used as a form of subsistence by part of the
population. It consists of using birds of prey
(mainly falcons) to hunt. Trained birds are
typically carried, hooded, and perched on
their masters’ arms. When released, they
fly at high altitudes looking for prey, and
then dive toward the ground to hunt it.
They carry the prey back to their
masters, who reward them with food.
The basic training process takes a
little over a month and a half.
HORUS, THE FALCON, is an important god in
Egyptian mythology. His eyes represent the sun
Dressing Up in Feathers
Almost all cultures have used bird feathers
for decorative and ritualistic purposes. Their use
as ornaments extended to North and South America,
Africa, and the Western Pacific. North American
indigenous peoples featured them on their war
outfits, Hawaian kings wore them on their royal
costumes, and the Mayans and Aztecs used them
in works of art.
bod wy COMPETITOR BIRDS
as When birds share a habitat
with humans, they often
compete for resources (light,
water, space, and nutrients).
a 3 This is the case with birds
-_ that feed on cultivated
; crops. Urban areas, which
. have buildings that offer
good nesting sites, attract
8 many birds. This fact can be
commonly observed in
squares and open spaces,
where pigeons and sparrows
form veritable flocks.
r-
and the moon, and together with Sethhe ELEMENTS
watches over the boat of Ra, which carries the - : ete ific cloth
dead away on the Nile. Wry i . dy irds and masters wear specific clothes.
Seer eS A , In addition to gloves, hoods, and straps,
. ; wd Roe radio transmitters are now also used to
Ww : : hy
locate the birds as they fly.
@
PIGEON Sometimes
their numbers in
urban areas become
excessive.
SPARROW The
sparrow is one of the
birds best adapted to
the urban environment.
NORTH AMERICAN
INDIGENOUS MAN
wearing a war
costume covered
with feathers
| environment.
"i UMANS AND BIRDS
ow to Get to Know Birds
_ rnithology (from the Greek ornitho, “bird,” and logos, “science”) is a
branch of zoology that studies birds. Ornithologists and a great number
of bird lovers, who enthusiastically want to know more about these
creatures, carry out the task methodically and patiently. They observe,
analyze, and register birds’ sounds, colors, movements, and behavior in
their natural environments. To undertake this fieldwork, they develop
methods and techniques and use
technological resources to track
pte
ie te STUDIES
om +) Many studies on
anatomy, physiology,
and genetics of
specimens and different bird species
; nucse Gees are carried out in
happens to the laboratories.
times of the year. —
Although seemingly a ih «
small detail, clothes can
be a hindrance. They
CAMERA WITH
ZOOM LENS
A camera with a
powerful lens
provides the
opportunity to
record details
that simple
cameras cannot.
BINOCULARS
They make it possible
to see details in color
and shape without
disturbing the birds.
Their usefulness
depends on the power
of their lenses.
Catching Birds
MIST NET
These fine nets are usually
placed over swamps or
marshes, and they can
catch small birds. Once the
birds are identified with a
ring or some other tag,
they are set free.
CANNON NETS
These nets are “shot” over
birds using cannons or
rockets. They unroll and
catch birds as they are
eating or resting. They are
used to catch large birds.
HELIGOLAND TRAP
ists of a large barbed-
innel or corridor that
in a box. Birds caught
like this are tagged so that
they can be monitored and
studied later on.
Scientists take ge of molting to study
ey are changing
irds stand on their
it difficult to
e any rings on
ic chips are
planted in their skin. The
latter technique is less
harmful because it does
7) : hurting the bird or causing it
nge its activity.
not potentially hinde
the animal.
BIRDS 85
The Marking of
Captured Birds
This technique provides data on
migration, survival, and
reproduction rates, among other data.
The bird should not suffer adverse
effects in its behavior, longevity, or
social interactions. Under no
circumstances should this en
procedure hurt a bird. To avoid
hurting birds, rings are
designed to be placed on
them rapidly and easily, yet
to stay in place until the
research is completed.
RINGED
Numbered aluminum rings
are used. When placing one
ona bird, one should make
sure that it slides and turns
around the tibiotarsus to avoid
WING MARKERS
They are very visible and can be codified for individual
identification. They stay on the bird = of time and
are normally used on birds of prey.
NECK MARKERS
When placed appropriately,
necklaces are effective markers
with few adverse effects on
geese, swans, or other aquatic
birds with long necks.
NASAL MARKERS
These are colored, numbered plastic
disks placed on the bill. They are
fastened to the nasal orifices of
aquatic birds.
PAINTS AND DYES
Birds that visit environments with dense
vegetation are normally marked with nontoxic
colorings on the feathers of their highest and
most visible body parts.
eS ener az
- = ~ —
“? -
: we
ow > oa os
86 HUMANS AND BIRDS BIRDS 87
Among Us PARKS AND GARDENS
Royal peacocks and green peafowls share these
places, where they can find the microhabitats of
The Urban Environment
I This setting is characterized by environmental and
climatic factors that are different from the natural
ones. It has more varieties of plants, higher average
he urban environment presents opportunities for birds. It offers advantages In finding food and insects on which they feed. Parks and gardens may temperatures, less wind, more rain, cloudier skies, and less
shelter. People, young and old, give bread crumbs to these interested visitors. When birds come Have pans Mat ateivistted hy otter Diu species a solar radiation, Polluted air and soil are harmful factors for
— : : . . . e . well. Few species nest in these places because these both humans and birds.
to cities, houses and parks offer them protection. They can find more options when it comes to spaces offer little quiet.
building a nest. Seagulls and owls have changed their behavior by adapting to the city, and other
species, such as some sparrows, are no longer able to survive without a human presence. However, not
everything is an advantage. In the city, birds have to face dangers and obstacles that do not exist in ree tia
were originally
migratory, but as
10% 15% 1.5°
H H . li . 4 RAIN WIND TEMPERATURE
their natural habitat: a utility wire or a car can be fatal. thy ated ae oe TenreRs
nonmigratory. DECREASE DOWNTOWN
GROVE
Where to Find Them URBAN CENTERS
With the arrival of cold weather, different bird species from the
countryside and the mountains come to the city. In general, they
stay until the beginning of spring. In the winter, more birds, such as
In big cities, groups of birds can be found in different areas. Busy and
noisy areas, such as squares, parks, and gardens, attract many species.
Calm, deserted spaces, such as cemeteries or deserted buildings, are chosen by Ghiffchafis) great tits, and robing, caniée observed in cities SPARROWS
birds in search of peace. Other places where birds choose to eat and sleep include Small birds with a
plots and landfills with lots of food, as well as nooks in high places, such as highly varied diet
balconies, belfries, and roosts.
FALCONS
Diurnal birds of prey.
They nest on the roofs
of high buildings.
PLOTS AND CEMETERIES
Plants with seeds usually grow in these places,
which are located far from urban centers. For
this reason, magpies and nightingales favor them.
DAY/NIGHT
Artificial night lighting
intensifies birds' activities.
They organize their tasks
according to street lighting.
PIGEONS
spend a lot of time
together. They are
granivores but eat all
kinds of food.
SWIFTS
are insectivores.
They catch their
prey in flight.
ABANDONED
BUILDING
nest in holes or crannies,
always near water.
STORKS
build their
on rooftops.
>. ROBINS
NN They get close only
\ to find food. Their
\ trills and plumage Population Control
are attractive.
ests
Without enough predators and with an
abundance of food, urban bird
populations grow exponentially.
FEEDER
WITH DIET f |
FRUITS Some species, which are 9
veritable strategists, benefit
for Ei tivities. F RAVENS, CROWS, AND
rom ae ad ay af RELATED BIRDS
example, seagulls can feed on LIVE IN MOSCOW.
garbage; great tits drink milk
from containers by adroitly
uncapping them; and some
magpies have learned to tear l 60 ¢ ¢ ¢
cardboard containers to eat 9
SEAGULLS
usually fight among
themselves for the food
they get from landfills.
OWLS
LANDFILL Belfries or abandoned the eggs inside. Laer
buildings are the homes or DESCEND ON THE SQUARES
AND STREETS OF BARCELONA.
dormitories of these birds.
j
88 HUMANS AND BIRDS a BIRDS 89
2"
le When porapaed to other farm animals,
birds grow and reproduce easily. They
need to have a place with appropriate |
temperature, humidity, a ett in order | }
Bird Domesticators 4 Sa
have been selectively *.
bred by humans for
he breeding of birds in captivity has great social and ee: ae ae ao
economic value. This activity is carried out/alljover the cam WA cnn NN Pa) we
on industrial poultry farms and family farm ba f) fl i my
raised for consumption and sale. A great variety of domestic birds 1
have been developed from species inhabiting natural environments. |
We use their flesh and eggs as food and their feathers in coats to
protect us against the cold. We also use birds for communication
and as colorful and melodic pets. They are so dependent on people
that in some cases they cannot survive when they are freed.
to yield the desired amount of meat or eggs.
For this reason, it is necessary to maintain
continuous environmental and sanitary Control ==
of the area in which they are bred, Ideally they
should be able to walk, run, scratch the earth in
search of food, and take sunbaths. Additionally,
to protect them from predators and from
inclen ent awecttier, it is important to\shelter
At Your Service
fe Domestic birds have been bred from the
following orders: Galliformes (hens, quails,
turkeys, and pheasants), Anseriformes (ducks
and geese), Columbiformes (pigeons),
Passeriformes (canaries), and Psittaciformes
(parakeets and parrots). In poultry farming, they
are divided according to their use: barnyard birds
(Galliformes, Anseriformes, and Columbiformes)
and companion birds or pets (Passeriformes and
Psittaciformes). Commercial poultry farming of
barnyard birds generates high revenues
worldwide. Farmers can take advantage of the
fact that birds are very active during the day, MIXED DIET ~
that they readily live in groups, and that they : Birds look for insects and
have a high reproductive rate due to polygamous plant shoots as they peck
behavior. Pets have commercial appeal, with the soil. The breeder
their colorful plumage, ability to express TURKEY GOOSE DUCK Y complements this diet
4 Ten es drink
7, oad we 05 Ja
’ 1) of w
he farmer ae
them with water in
We which co
themselves, and friendliness toward humans. On the American continent, Contemporary domestic These birds are an with ptitionglly
These characteristics make them much- these birds were domesticated breeds descend from wild important source of —
appreciated pets. by the indigenous pre- Asian and eastern Lid rt bas ee ae
Columbians from a wild European species. They are eee out
Mexican species called voracious, which makes. consumption anductsis
Meleagris gallopavo gallopavo. fattening them easy. less widespread.
BIRD FLU
This disease, also called avian influenza A, PATHS INTO THE BODY Conjunctiva SIZE COMPARISON
is caused by a virus whose strains have Digestive Tract Respiratory Tract )
various levels of virulence. It Urogenital Tract Needles Bacteria
disseminated from Asian markets, where Skin Virus
Wounds
the overcrowding of domestic birds is
common. This promoted the spread of the
disease to wild birds. As of 2006, more
than 30 million birds had succumbed to
this disease. Cats, pigs, and human beings
have also been infected.
The domestication of birds is a very old activity, as shown by records from
different cultures in different parts of the world. It was related to the
adoption of a sedentary way of life by human populations.
4
The virus can be
transmitted to the
most common of
domestic birds:
chickens.
The H5N1 virus is
transmitted to
5000 BC 2000 BC 1492
AIRMAIL
For more than 1,700 years, human humans through
beings have used pigeons to send THE COMMOTION AND H Fi y i
messages. Armies have used them FEAR OVER DISEASE ne econ ‘ I Far East Mexico
as communication aids during HAVE REDUCED THE Ducks carry the : : e records — Descendants of the royal The Spanish colonizers
wars. Pigeon keeping is the DEMAND FOR THE H5N1 virus but domestic geese duck (Anas platyrhynchos) _ encountered turkeys
practice of breeding and preparing CONSUMPTION OF PreuiMonente Ada: cinni d Aicated in thi d Rieatedib
pigeons to become messengers, a DOMESTIC BIRDS IN oe Wy eeeeening §=were'comes: ical geal b Is : ones ey,
task that makes the most of their MAJOR EUROPEAN this disease. 5000 BC. area of the Asian continent inhabitants of the
agility and intelligence. CITIES BY HALF.
(what is now China). New World. ~ 3 —_
90 HUMANS AND BIRDS
the world's avifauna is to learn about the
extinction of birds and its magnitude. @
The Most Important Causes
Fl Birds are very sensitive to changes in their habitats,
Leff and this is the main cause of extinction (87 percent
of species are affected by it). Excessive hunting is another
of the greatest dangers, affecting 29 percent of the
endangered species in the world. The introduction of
foreign species is yet another major danger, jeopardizing 28
percent of species. In addition, the intervention of human
beings through the destruction of habitats and the
introduction of pollution combined with the occurrence of California
natural disasters harms more than 10 percent of species.
POISONING
Most birds of prey 666666686
are endangered by oe 86 om egies Pesticides are
; Pesticides
the excessive use of sprayed on crops
nonbiodegradable to eliminate pests,
pesticides. and they stick to
the seeds.
Granivorous Birds
NORTH
AMERICA
UNITED STATES
Endangered Species
ince early civilization, people have affected the Earth's environment. The cutting
of trees in rainforests and woodlands has destroyed many bird habitats, the loss
of which is the leading cause of bird extinctions today. Also, the introduction
of animals such as cats, dogs, and rats to new areas has created a
threat for many bird species. Indirect poisoning with
pesticides, the trafficking of exotic birds as pets, and the sale
of feathers have done further damage to many species.
Fortunately, all is not lost. The first step to conserving
CALIFORNIA
CONDOR
Gymnogyps californianus
Until 1978, there were 30
specimens in the wild. Bred
in captivity, new specimens
have been set free since
1993. Their adaptation is
being studied.
Atlantic
Ocean
Everplades @ HYACINTH MACAW
Anodorhynchus hyacinthinus
It is estimated that 1,000 to
9,000 specimens live in
CENTRAL
: the Amazon.
AMERICA
Pacific
Ocean
COLOMBIA
Small quantities of
e e w poison in seeds
accumulate in larger ECUADOR
x "4 amounts in birds
and other
Birds of Prey granivorous animals. PERU
C-— ROYAL CINCLODES
Cinclodes aricomae
live on humid mountain ranges,
ie chee MANGROVE FINCH at altitudes between 11,500 and
in tah eas Camarhynchus heliobates 15,000 feet (3,500-4,500 m).
easing | There are about 100 Their number is unknown.
pesticides impacts aes f
hunting birds the remaining species on the
most. Galapagos Islands. SOUTH
PEREGRINE ANE
FALCON
@ Nahuel
Huapi e
SAVING THE PEREGRINE FALCON FROM EXTINCTION B | r d
1942 1960 1970 1986 INTERNATIONATI
There were 350 Peregrine falcons Falcons were 850 birds were BirdLife International
couples of disappeared in the wild bred in captivity set free in the It monitors endangered species and
peregrine because of excessive at Cornell southern develops conservation programs.
falcons in the use of pesticides University, tobe United States.
United States. (DDT and dieldrin). set free later.
BIRDS 91
CLASSIFICATION OF RISK EXTINCT BIRDS ly m
Extinct in the Wild Critical Risk Endangered Vulnerable Although the responsibility ISG, cs ma eN yl *
Species surviving Extinction is Fast-decreasing _High risk of of human beings is LPS ot ‘
only in captivity imminent population extinction in the wild undeniable, many species
became extinct because of
natural phenomena.
BIRDS OF THE WORLD However, all the extinctions
7,775 1,212 4 179 from the 18th century to date j
Non-endangered Endangered Extinct in At critical are related to human activities. Dodo from
species (or no species the wild risk Mauritius
information Quickly
available) 679
788 Vulne:
Species about to
be endangered
EUROPE
INDIAN VULTURE
Gyps indicus
Its population has
decreased significantly
as a result of the
veterinary use of
diclofenac. The vulture
eats the carrion of animals
treated with this drug
and becomes poisoned.
rable
AFRICA
@ Prince
Albert Tsavo @
Serengeti @
Wankie @
@ Kriiger 20 4
100 +
A 80 +
Alarming Data
§@ Five percent of the planet's surface = ¢g
(Lefl houses three fourths of endangered
species. This area coincides with tropical
2 ees oo 40 +
regions where biodiversity is greater. For
this reason, tropical countries top the list
to the right. On some islands, the 20 +
proportion of endangered birds is very
high: in the Philippines and in New Zealand, 0
it includes 35 to 42 percent of avian fauna.
350 l
Endangered
MALAYSIAN COCKATOO ———O
Cacatua haematuropygid PHILIPPINES
It is estimated that there are
: between 1,000 and 4,000
indian individuals remaining. It was
Ocean hunted indiscriminately.
INDONESIA
exterminated by
colonizers and
SPECIES HAVE GONE
EXTINCT SINCE THE
18TH CENTURY. seafarers in the
17th century
ASIA
Pacific
Ocean
BENGAL VULTURE
Gyps bengalensis
From 1996 to date, its
population has fallen by 95
percent, especially in India.
CHINA }
Celebes
LEGEND
@ SHELTERS AND SANCTUARIES
FOR ENDANGERED BIRDS
YELLOW-CRESTED
COCKATOO
Cacatua.sulphurea
2.0%
In three
generations, its
population fell by 80
percent because of
hunting.
1s is OF THE EARTH'S aie hy ISLAND
SURFACE IS HOME TO ALL vo
Anas nesiotis
ENDANGERED
78 76 75
Indonesia Brazil Colombia China Peru
BIRD SPECIES.
Only 50 individuals remain
OCEANIA _ because of the introduction
of mammals to the island.
74
NEW
ZEALAND
42
35
25
20
India Philippines Ecuador New United
Zealand States
92 GLOSSARY
Glossary
Adaptation
Change in the body of a bird or another
animal that allows it to reproduce better in
a given environment
Adaptive Radiation
Evolution of an initial species, adapted to a
given way of life, into other species, each
adapted to its own way of life
Aerodynamic
Having an appropriate shape to decrease
resistance to the air. Birds' bodies are
aerodynamic.
Alulae
Rigid feathers whose function is to decrease
air turbulence during flight
Amino Acid
Molecule from which proteins are produced
Ancestor
Progenitor, more or less remote, that passes
down a set of characteristics to its
descendants
Angle of Attack
The change in position of a bird's wing to
increase or decrease speed and altitude
while hunting prey by air
Apterylae
Naked areas of the skin where feathers do
not grow
Atrophy
Significant decrease in the size of an organ.
The wings of nonflying birds have undergone
atrophy during evolution.
Barbs
Thin, straight, parallel blades, perpendicular
to the shaft. They resemble the leaves of a
palm tree.
Bill
Hard cover of a bird's mandibles; also called
the bill.
Biodiversity
Variety of species that live in a given natural
or artificial environment
Biogeographic Regions
Geographic regions that biologists analyze
to determine the distribution of animals and
other living organisms, according to the
geographic conditions of a place. Migratory
birds usually travel through different
biogeographic regions between winter and
summer.
Biped
Aero-terrestrial animal that walks on its
posterior limbs. Birds are bipeds.
Briny
Water sample or body of water containing
between 0.08 and 4.25 ounces (0.5-30 g) of
salt per gallon of aqueous solution
Bronchus
Each of the branches into which the trachea
divides. The syrinx originates in the bronchi.
Calamus
The lower part of the vane that is wider,
hollow, and, in general, naked. The feather is
attached to the skin through the calamus.
Camouflage
A characteristic that enables the animal to
blend into its environment. It allows the
animal to go unnoticed in the presence of
predators.
Carnivore
An animal that feeds on meat
Carrion
The remains of dead animals used as food by
some birds or other animals. Vultures are
scavengers (i.e., animals that feed on
carrion).
Center of Gravity
Point at which the sum of all the
gravitational forces that act on a body
converge
Cere
Thin skin layer that covers the base of the
bill
Chick
A baby bird that has just come out of the
eggshell and that has not yet left the nest.
Its diet and safety depend on its parents.
Chorion
One of the coverings that wraps the embryo
of reptiles, birds, and mammals
Class
One of the many divisions scientists use to
classify animals. Birds form a class of their
own.
Climate
Average temperature, humidity, and
pressure that determine the atmospheric
conditions of a region and that are related to
other geographic characteristics of that
region
Cloaca
The widened and dilatable final portion of
the intestine of a bird or other animal in
which the urinogenital tubes converge
Courtship
Behavior patterns that males and females
follow to try to attract partners
Coverts
Layers of contour feathers that provide a
bird's body and wings with support and an
aerodynamic surface
Crepuscular
Active at dawn or twilight, when there is
little light
Crest
Extended or raised feathers located on the
upper part of a bird's head
Crop
Membranous sac that communicates with a
bird's esophagus, where food is softened
Dermal Papilla
Structure from which a feather develops. It
is composed of epidermal and dermal cells.
Display
Behavior directed at attracting the
attention of a partner. It can also be done to
threaten or distract another animal.
Distribution
Place where a species is located. It includes
the area the species occupies in different
seasons.
Down Feather
A very thin and light feather, similar to silk,
that birds have underneath their external
plumage. Down feathers constitute the first
plumage of chicks.
Ecosystem
Community of living beings whose vital
processes are interrelated and develop
according to the physical factors of the
same environment
Egg
Large rounded shell, laid by a female bird,
that contains a yolk and a white. If
fertilized, the egg has a tiny embryo that
will develop into a chick (the chick feeds
itself on the yolk and white). When ready,
the chick will break the eggshell.
Egg Tooth
Sharp calcium growth, in the shape of a
tooth, that forms on the tip of a chick's bill
during the embryonic phase. The chick uses
the egg tooth to break its shell at birth.
Environment
The natural conditions, such as vegetation
and land, that surround animals and
influence their development and behavior
Epiphysis
Endocrine gland located below the corpus
callosum in the brain. It produces a hormone
that regulates sexual activity.
Evolution
Gradual process of change that a species
undergoes to adjust to the environment
Extinct
No longer existing. Many bird species are
now extinct (for example, ictiornites).
Feather
Each unit of the covering (plumage) of a
bird. The feathers are composed of a hard
substance called keratin. They have a long
quill, to which two blades are joined. The
blades—formed by a great number of barbs,
uniformly distributed—give the feather its
shape and color.
Fertilization
Union of the reproductive cells of a male and
a female that will create a new individual
Field Mark
Natural distinct feature or artificial
identification of an individual of a bird species
BIRDS 93
that helps ornithologists distinguish it from
other individuals of the same or other avian
species
Fledgling
Very young bird that lives in the nest where
it was raised
Fossils
Vestiges of ancient creatures of different
types (vegetal or animal) on a stone
substratum. Fossils can be found in the
geologic strata of the Earth's surface.
Gastric Juice
Set of fluids produced by the stomach
glands of birds and other animals
Gizzard
Muscular stomach of a bird. It is very
robust, especially in granivores, and it is
used to grind and soften the food by means
of mechanical pressure. The food arrives at
the gizzard mixed with digestive juices.
Gland
Type of structure that is present in most
multicellular living beings. It produces
substances that act either inside or outside
a bird's body.
Gonad
Organ that makes male or female gametes.
In birds, the testicles and ovaries are
gonads.
Granivore
Bird that feeds on seeds or grains. Many
birds are granivores (for example, parrots
and toucans).
Gular Sac
Skin fragment in the shape of a sac that
hangs from the lower mandible of certain
birds (for example, pelicans)
94 GLOSSARY
Habitat
Native or natural environment of an animal
or plant
Hatching
Cracking of the eggshell so that the bird
cancome out
Histologic
Related to tissues and their study. When the
anatomy of a bird is studied, the tissues that
form the bird's organs are analyzed.
Hormones
Secretion of certain glands that circulates
through the body. They excite, inhibit, or
regulate the activities of organs or of
systems of organs.
Horn
Made of horn or of a consistency similar to
that of horn. The bill of birds is hornlike.
Hypophysis
Internal secretion organ located at the
hollow of the skull's base (called silla turca).
It is composed of two lobes: one anterior
and glandular and the other posterior and
nervous. The hormones produced by the
hypophysis influence growth and sexual
development, among other things.
Hypothalamus
Region of the encephalon located at the
cerebral base, joined to the hypophysis by a
nerve stem, in which important centers for
vegetative life are found
Incubation
The act of keeping the eggs warm so that
the embryos inside can grow and hatch.
Usually the chick's parents use their own
bodies to warm the eggs, but some birds use
sand or decomposing plants to cover them.
Insectivore
Bird that eats insects as part of its diet
Instinct
Innate behavior that a bird or other animal
develops and that is not learned. The
offspring of ducks start to swim by instinct.
Invertebrate
Animal that lacks a spinal column. Worms,
crabs, and jellyfish are examples.
Lethargy
Sleep through which a bird can reduce its
cardiac rhythm and its body temperature to
save energy, especially at night and during
extended periods of cold
Malpighian Layer
Layer of epithelial cells that forms the bird's
epidermis
Mangrove Swamp
Type of ecosystem often considered a type
of biome. It is composed of trees that are
very tolerant to salt. These trees are found
in the intertidal zone of tropical coasts.
Areas with mangrove swamps include
estuaries and coastal zones.
Migration
The movement of birds from one region to
another; it usually takes place in the spring
and fall. It is also common among other
species of animals.
Molt
Process through which birds lose old worn
feathers, replacing them with new ones
Monogamous
Birds that mate with only one individual of
the opposite sex. Many penguins have
monogamous behavior.
Morphology
Study of the form of an object or structure.
For instance, the morphology of the feet of
birds is an area of study.
Nectar
Sweet and sugary secretions found in
flowers that attract birds and other animals.
Hummingbirds feed on nectar.
Nidicolous
A helpless chick that depends on its parents’
care after birth
Nidifugous
A chick that can move and leave the nest as
soon as it breaks its shell. In less than a day,
such chicks can move agilely.
Nocturnal
Active at night. Many birds of prey, such as
owls, specialize in nocturnal hunting.
Nutrient
Any substance obtained through diet that
participates in the vital functions of a living
being.
Omnivore
Bird that has a varied diet, including animal
and vegetal foods
Pelagic
Birds that live in areas over open waters,
away from the coast
Pellet (Bolus)
Small, hard mass that some birds
regurgitate (vomit). It contains parts of the
food that they could not digest, such as
bones, fur, feathers, and teeth.
Pigment
Substance that colors the skin, feathers, or
tissues of animals and plants
Piscivore
Birds living in continental or oceanic waters
that feed on fish
Pollution
A consequence of human actions for natural
environments. The emission of industrial
gases into the atmosphere, for example,
produces pollution.
Polygamy
Reproductive relationship between one
animal of one sex and several animals of the
other. When one male mates with several
females, it is called polygyny. Only rarely do
females have multiple male reproductive
partners (polyandry).
Population
Set of individuals of the same species that
live together in the same space at the same
time
Predator
Animal that hunts other animals. Birds of
prey hunt other birds, mammals, and
vertebrates.
Prey
Animal hunted by another to serve as food
for the latter. Animals that hunt prey are
called predators.
Protein
Organic macromolecule that is part of living
beings. By including proteins in their diet,
birds get the necessary amino acids to build
their own organs.
Protein Cord
Embryonic structure: each of the two
filaments that sustain the yolk of the egg
within the white
Proventriculus
The first portion of the stomach, or the true
stomach, of a bird. The other portion of a
bird's stomach is the gizzard.
Rectrices
Technical term used by ornithologists to
describe a bird's tail feathers
Scale
Dermic or epidermic layer that totally or
partially covers the feet of birds. They are
reptilian vestiges.
Song
Sound or series of sounds produced by a
bird to demarcate its territory or to find a
mate. The songs of birds can be simple or
elaborate, and some are very melodic.
Songbirds
Singing birds. Passerines include songbirds.
Species
Set of individuals that recognize themselves
as belonging to the same reproductive unit
Sternum
Central chest bone. The sternum of flying
birds has a large surface in which muscles
are inserted.
Survival
A bird's ability to face the demands of its
environment and of intra- and interspecies
relationships
Swamp
Depression on the ground in which water is
gathered, sometimes called a marsh. Its
bottom is more or less boggy. It is the
habitat of many wading birds.
Thermal
Hot air current that rises. Many birds make
use of it to gain height effortlessly.
BIRDS 95
Theropods
Group to which carnivorous dinosaurs
belong
Training
Teaching an animal new skills. Carrier
pigeons are trained.
Tundra
Vast plains without trees in the Arctic
regions of northern Asia, Europe, and North
America
Uropygial Gland
Produces an oily secretion that birds, using
their bills, spread on their feathers to make
them impermeable
Vertebrate
Animals that have a spinal column, such as
birds, fish, reptiles, amphibians, and
mammals
Virus
Infectious agent that depends on a living
being to reproduce. Avian flu is transmitted
this way.
Vulnerable
Birds that are endangered in their natural
habitats
Yolk
Yellow part of the egg. If the egg is
fertilized, a small embryo grows that will
use the yolk (and white) as food.
Young
Bird or any other animal at an early stage of
life. Some young show color patterns that
are very different from that of adults of the
same species, which makes it difficult for
predators to identify them.
96 INDEX
BIRDS 97
Index
A
adaptation
aquatic life, 5
cellulose digestion, 57
environment, 66
flightless birds, 29
flying, 8f, 12, 24-25
foot, 20-21
hatching, 53
marine birds, 70, 71
perching, 13, 79
swimming, 68
urban habitats, 83
walking, 7
adaptive radiation, 62
aero-terrestrial habitat, 65
African ostrich
flightless birds, 68-69
weight, 8
Afrotropic region, 67
albatross
birth, 52
classification, 64
gliding, 35
incubation (egg), 52
migration routes, 59
wings, 29
altitudinal migration, 58
anatomy
external features, 8-9
internal organs, 14-15
skeleton and musculature, 12-13
See also specific body parts by name,
for example, wing
ankle, 21
annual life cycle, 42-43
Anseriformes (bird classification), 64, 72
Antarctic bird: See penguin
apteria, 27
Apterygiformes (bird classification), 65, 69
aquatic bird
classification, 64, 65
foot adaptation, 20
physical adaptations, 5
powder down, 27
See also marine bird
arboreal theory (evolution), 24
Archaeopteryx, 10-11
arctic tern, migration, 39, 58
aricari, bill, 19
artery, 15
Asia
bird domestication, 89
migration routes, 59
Australasia, 67
Australian bowerbird, courtship behavior, 46
avian influenza A, 88
Aztec culture, 82
B
bald eagle
birds of prey, 74
talons, 21
bar-headed goose
flight altitude, 38
migration routes, 59
barn swallow, migration, 58, 59, 79
bat, wing, 24
beak: See bill
Bengal vulture, 91
bill, 18-19
birds of prey, 74
ducks, 73
food filtration, 56
identification, 9
modern bird, 12
parrot, 76
binocular vision, 17
binoculars, 84
biodiversity
endangered species, 90-91
geographical regions, 66-67
running birds, 69
biogeographic region, 66-67
bird flu: See avian influenza A
bird of prey, 74-75
pesticide poisoning, 90
vision, 17
birdcall,
communication, 44
warnings, 61
birdsong, communication, 44-45
birdwatching, 84
black grouse, courtship display, 31
black swan, flight speed, 38
blackbird, urban habitats, 87
blood circulation: See circulatory system
blue-and-white swallow, 80
blue-footed booby, courtship behavior, 43
bone: See skeletal system
brain
Archaeopteryx, 10
sound production, 44
breathing: See respiratory system
brown pelican, 70
Bubo capensis, 6, 7
Buffon, Georges-Louis Leclerc, Count de, 66
C
California condor, captive breeding, 90
call: See birdcall
camera, 84
camouflage
defense strategies, 60
molting, 32
Campbell Island teal, 91
canary, 88
cannon net, 85
Cape gannet
marine birds, 70
migration routes, 58
captive breeding, 90
carnivorous bird
gizzard, 14
See also bird of prey
carpal bone, 13
carpometacarpus, 13
Caspian tern, migration routes, 59
Casuariiformes (bird classification), 65, 69
Central America, migration routes, 58
Charadriiformes (bird classification), 64, 65, 73
China, birds in symbolism, 82
chough, flight altitude, 38
circulatory system, 15
classification, 64-65
claw, 21
climbing, foot adaptation, 20
cockatoo, endangered species, 91
collarbone
Archaeopteryx, 11
modern bird, 12-13
coloration, 77
flesh, 12
seasonal changes, 32
common loon, 70
common spoonbill, feeding, 73
common waxbill, 20
communication, 44-45
compass-and-triangulation system
(migration), 59
condor
captive breeding, 90
dimensions, 75
contour (feather), 26
coracoid, 13
courtship, 46-47
annual life cycle, 43
black grouse, 31
hummingbird, 37
tail feathers 30
covert (feather), 26
crane
courtship behavior, 47
migration routes, 59
crop (esophagus), 14
crossbill, bill, 19
curlew sandpiper, migration routes, 59
cursory theory (evolution), 24
D
Darwin, Charles, 10
data collection, 85
defense
camouflage: See camouflage
claw, 21
individual behavior, 60
group behavior, 61
diet, 56-57
adaptation of bill, 18
courtship food, 46
dive fishing, 71
flight needs, 36-37
nidicolous birds, 55
nidifugous birds, 54
Universe of Birds, 5
digestive process, 14
digestive system, 14-15
dinosaur fossil, 10
diurnal bird of prey, 74
See also specific birds by name, for example,
eagle
diving bird, 73
dodo, 91
domestication, 88-89
dove, symbolism, 83
down (feather), 26
duck
feeding, 62, 72
human consumption, 88
swimming mechanism, 72
dust bath, 27
E
eagle
birds of prey, 74-75
carrying ability, 25
feeding strategies, 57
migration routes, 59
speed, 39
symbolism, 82-83
talons, 20, 21
ear
external anatomy, 9
senses, 16
egg, 50-51
incubation, 52
egg tooth, 53
Egyptian mythology, birds in symbolism, 82-83
eider, flight speed, 38
embryo formation, 50-51
endangered species, 90-91
epiphysis: See pineal gland
equipment, bird watching, 84-85
esophagus, crop, 14
Eurasian eagle owl, 74
Europe, migration routes, 58-59
evolution, 10-1]
flight adaptation theories, 24
excretory system, 14
extinction, risk, 91
See also endangered species
eye, 17
eyesight: See vision
F
falcon
bill, 19
speed, 39
urban habitats, 86
falconry, 82
false knee: See ankle
farm production, 88-89
feather
camouflage, 60
color, 77
external anatomy, 8-9
flight, 26-27
growth and molting, 32-33
human uses, 83
parrot, 22-23
seasonal color changes, 32
98 INDEX
BIRDS 99
tail function, 30
See also tail
feeding strategy, 57
femur, 13
finch, 90
fish, in diet, 57
fishing method, 71
flamingo
bill, 19
food filtration system, 56
milk feeding, 56-57
flapping flight, 36-37
flapping wing, 12
flight, 22-39
adaptations and mechanisms, 8, 12
diet, 56-57
oxygen needs, 14
See also wing
flight pattern, 35
flightless bird, 68-69
geographic distribution, 67
wings, 29
flying animal, 25
foot, 20-21
Archaeopteryx, 11
birds of prey, 75
external anatomy, 9
marine adaptations, 70
perching adaptations, 13, 79
skeleton and musculature, 13
zygodactyl, 77
fossil record
bones, 24
German findings, 10
freshwater bird, 72-73
frigatebird, reproductive season, 43
fruit, in diet, 57
fulvous whistling duck, 72-73
furculum: See collarbone
G
Galliformes (bird classification), 65, 69
geographic distribution, 66-67
Passerines, 79
Germany, fossil findings, 10
gizzard, types, 14
gliding, 34-35
golden plover
flight endurance, 39
migration routes, 58
goose
domestic breeds, 88
flight altitude, 38
flight pattern, 35
goshawk
birds of prey, 74
courtship behavior, 46
grain food, 57
granivorous bird, gizzard, 14
grasping mechanism, 13
foot adaptation, 20
great crested grebe
courtship behavior, 46
lobed toes, 21
greenfinch, bill, 19
grey crowned crane, courtship behavior, 47
group defense behavior, 61
growth stage
nidicolous birds, 55
nidifugous birds, 54
gull
herring gull, 70
urban habitats, 86
H
habitat, 65
destruction, 90
direct observation, 84
terrestrial, 65
urban habitats, 83, 86-87
woodpecker, 76
See also aquatic bird; freshwater bird;
marine bird
hammerkop, feeding, 73
hatching, 52-53
postnatal development, 54-55
See also egg
hatching muscle, 53
hawk, bill, 74
hearing, 16
heart, 15
Heligoland trap, 85
heron
bill, 19
feeding, 73
imperial heron, 27
tricolored heron, 20-21
white heron, 4, 5
herring gull, 70
hoatzin, 64, 66
Holarctica, 67
human anatomy
comparison, 10
leg, 21
vision compared, 17
human interaction, 82-83
domestication, 88-89
humerus, 13
hummingbird
bill, 19
courtship behavior, 37
external anatomy, 12
flight mechanism, 37
internal organs, 14-15
migration routes, 58
Passeriformes, 78
ruby-throated hummingbird, 58, 67
tongue, 57
wine-throated hummingbird, 8
hunting bird: See bird of prey
hyacinth macaw, 90
hypophysis, 42
I
ibis, 73
identification, 9
captured birds, 85
See also classification
imperial heron, 27
imperial shag, 70
incubation (egg), 52
incubator bird, 54
India
domestication, 89
representation of god, 82
Indian vulture, 91
Indomalaya region, 67
insectivore, 57
J
jaw, 19
jawbone, Archaeopteryx, 10
Jurassic Period, Archaeopteryx, 10-11
K
keratin, 27
kiwi, 69
knee, 21
L
latitudinal migration, 58
laying (egg): See egg
Leclerc, Georges-Louis, Count de Buffon, 66
leg, 20-21
grasping mechanism, 13
muscles, 13
lek ritual, 46
lesser spotted eagle, migration routes, 59
life cycle, annual, 42-43
little masked weaver, nest building, 49
longitudinal migration, 58
loon: See common loon
lung, 15
lyrebird, 78
M
Malaysian cockatoo, 91
mangrove finch, 90
marine bird, 65, 70-71
gliding, 35
See also aquatic bird
marine glider, 34
marking (captured bird), 85
Mayan culture, 82
meat, in diet, 57
metabolism, 9
Mexico, domestication, 89
migration, 58-59
artic tern, 39
Passerines, 79
Universe of Birds, 4-5
mimicry of sound, 76, 78, 79
mist net, 85
molting, 32-33
monocular vision, 17
monogamy, 47
musculature, 12-13
mythology, 82-83
N
nasal marker, 85
Nearctic region, 66
neck marker, 85
nectar, 57
Neotropic region, 66
nest
construction, 49
types, 48
nesting, 5
partridge, 41
net, types, 85
nidicolous bird, 54, 55
nidifugous bird, 54
nocturnal bird, 74
See also owl
North America
indigenous peoples, 83
migration routes, 58
northern harrier, courtship behavior, 46
northern wheater, migration routes, 59
nostril, 71
nuptial display: See courtship
O
Oceania, 66
Origin of Species, The (Darwin), 10
ornithology, 84-85
ostrich
African ostrich, 8, 68-69
distribution, 67
ovenbird, 79
owl
birds of prey, 74
Bubo capensis, 6-7
diet, 57
urban habitats, 86
oxygen, consumption, 14
P
Palearctic region, 67
parental care (evolution), 24
parrot
feathers, 22-23
flight speed, 38
talking birds, 76
partridge
nesting, 41
red-legged partridge, 54
passerine (Passeriformes), 78-79
external anatomy, 9
100 INDEX
BIRDS 101
classification, 64, 65
pelican
brown pelican, 70
flight, 34-35
resting pose, 42-43
pelvis, Archaeopteryx, 11
penguin
external anatomy, 8
feather coverage, 27
incubation (egg), 52
mating behavior, 47
molting, 32
observation, 85
swimming adaptations, 68
swimming speed, 39
perching
foot adaptation, 20
skeleton and musculature, 13
See also passerine
peregrine falcon
migration routes, 58
pesticide poisoning, 90
speed, 39
pesticide, poisoning, 90
pheasant, flight speed, 38
pigeon
incubation (egg), 52
messenger service, 88
milk feeding, 56-57
skeleton, 10
urban habitats, 83, 86
wing mobility, 11
pineal gland, 42
plumage: See feather
pneumatic bone, 13
Podicipediformes (bird classification), 65, 73
polyandry, 47
polygamy, 47
polygyny, 47
population control, urban habitats, 87
postnatal development, 54-55
poultry farming, 88-89
powder down, 27
preening, 27
ptarmigan, molting, 32
pterodactyl, wing, 24
pterylae, 27
puffin, 66
pygostyle, 11, 13
See also tail
()-R
quetzal, 76, 82
radius, 13
ratite, 69
raven, 19,78
religion, birds as symbols, 82-83
reproduction
courtship: See courtship
egg, 50-51
hypophysis, 42
reptile, bird evolution, 24
respiratory system, 15
rhea, 69
ribs, Archaeopteryx, 11
ringed bird, 85
robin, 80-81, 87
rockhopper penguin, 68
royal cinclode, 90
royal eagle, speed, 39
royal swift, flight speed, 38
ruby-throated hummingbird
bird distribution, 67
migration routes, 58
ruff, courtship behavior, 43
running bird
flightless birds, 69
foot adaptation, 20
running theory (evolution), 24
Ruppell's griffon vulture, 39
S
salt gland, 71
scale (bird skin)
feet, 21
types, 25
Scots dumpy rooster, spurs, 21
seagull, urban habitats, 86
seasonal color change, 32
seed food, 57
seizing: See grasping mechanism
sense, 16-17
external anatomy, 9
shoebill, feeding, 73
Siberian crane, migration routes, 59
sight: See vision
skeletal system, 12-13
Archaeopteryx, 11
legs, 21
running birds, 69
See also under specific topic, for example toe
skull
Archaeopteryx, 10
modern bird, 12
sleep regulation, 42
smell, 16
snow bunting, migration routes, 58
snowy egret, courtship behavior, 46
song: See birdsong
songbird
classification, 64, 65
distinction, 9
Passeriformes, 78-79
sound production
recording, 84
songbirds, 78, 79
talking birds, 76
South America
domestication, 89
migration routes, 58
species diversity, 66
sparrow
urban habitats, 83, 87
white-throated sparrow, 8-9
sparrowhawk, 74
species classification: See classification
speed, 38-39
spin tailed swift, speed, 39
spine
Archaeopteryx, 10
bones, 13
spoonbill: See common spoonbill
spur, 21
stability, 8
starling
defense formation, 61
flight speed, 38
sternum, modern bird, 12-13
stork
feeding, 73
flight speed, 38
migration routes, 58
urban habitats, 86
Struthioniformes (bird classification), 65, 69
swallow, 78, 79, 80
swan
flight altitude, 38
migration routes, 59
swift, urban habitats, 86
symbolism, 83
syrinx, sound production, 44, 79
T
tail, 30-31
Archaeopteryx, 11
pygostyle, 11, 13
tail feather, 8
talon, Archaeopteryx, 11
tarsometatarsus, 13
Archaeopteryx, 11
terrestrial animal, speed of movement, 39
terrestrial glider, 34, 35
terrestrial habitat, 65
territorial demarcation, 45
theropod, 10
thigh, 21
tibia, 13, 21
tibiotarsus, 21
toe
anatomy, 9, 13
Archaeopteryx, 11
types, 20
tongue
hummingbird, 57
internal organs, 15, 16
toucan
bill, 19
colorful birds, 76
touch, 16
Triassic Period, theropodan reptile, 10
tricolored heron, 20-21
turkey, 88
U-V
ulna, 13
urban habitat, 83, 86-87
vein, 15
velociraptor, 10
vibrissae, 27
vision, 16, 17
vulture
endangered species, 91
feeding practices, 75
flight altitude, 39
W
wading bird, 73
walking bird, adaptations, 7, 20
wandering albatross
migration routes, 59
distances, 40
wings, 29
water absorption, 14
waxhill: See common waxbill
white heron, 4, 5
white stork, migration routes, 58
white-throated sparrow, 8-9
wide bill, 79
wine-throated hummingbird, 8
wing, 28-29
birds of prey, 75
feathers, 9
gliding, 34-35
markers, 85
skeleton and musculature, 12-13
types and evolution, 24
wing loading, 29
winglet, 34
wingspan, 29
woodpecker, 76
wrist joint, Archaeopteryx, 11
Y-Z
yellow-crested cockatoo, 91
zone-tailed hawk, 74-75
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MAMMALS
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Wikelaalaarels
—
Close Relatives
Humans belong to the primate group. Hominids (orangutans,
gorillas, and chimpanzees) are the largest of these, weighing
between 105 and 595 pounds (48-270 kg). In general, males
are larger than females, with robust bodies and well-
developed arms. Their vertical carriage differentiates their
skeletons from those of other primates. Gorillas inhabit only
the equatorial jungles of western Africa. They support
themselves on their forelimbs while walking. Normally
c *: ae, their height varies between 4 and 6 feet (1.2-1.8 m),
but, if they raise their forelimbs and stand erect,
they can be over 6.5 feet tall (2 m).
CRANIUM ALWAYS 98° F
Relatively large (372 C)
compared to the size of The ability to
the body. And the brain maintain a constant
is more developed and body temperature is
more complex than that —_ not a characteristic
of any other animal. unique to mammals;
—— . birds also have that
a ability.
“SI
The tiny bones of the
ear form a system for
sensing. and
transmitting sound.
Formed by a single bone,
called the dentary, and
teeth specialized for each
function. The entire
Cranium has a very
simplified bone structure.
Homeothermy
The ability to keep body temperature
relatively constant, independent of
the ambient temperature.
Hibernating species are the
exception; they must lower
their body temperature to
enter into this state of reduced
metabolic activity. Contrary to
popular belief, bears do not
truly hibernate but rather
enter into a period of deep
sleep during winter.
GRIZZLY BEAR
(BROWN BEAR)
Ursus arctos
Limbs
Mammals have four limbs that are adapted for
moving about on land. Their forelimbs have certain
other abilities (swimming, manipulation, attack and
defense, protection). The exceptions are the
cetaceans, so adapted to marine life that they only
have two fingerless limbs, and seals (Phocidae).
ELEPHANT SEALS
Family Phocidae
Take Habitat
into Account
MAMMALS 15
Between every mammal and its natural habitat there is a
relationship that exists and is expressed in the animal's
physical characteristics. Just as the flippers of the
elephant seal are used to swim and hunt fish, mimicry and
running are vital for deer. Physiology is a special
instrument of adaptation to the environment, as in the
case of the camel.
f\ 4
Aquatic Temperate
Forests
i a
Desert Meadow or
Pastureland
Secrete the milk with
which the females feed
their young during their
first months of life.
These glands give the
class its name.
GORILLA
Gorilla gorilla
y
Formed by an otiter layer,
(epidermis), another
deeper ne (dermis), ¢ f
and a fatty substratu
that contributes to
*shomeothermy.
a a>)"
Tropical Tropical Taiga Tundra
Savanna Rainforest
} AN UNCOMMON PRIMATE
Humans have adapted to They often create tools to
almost all habitats through — help them adapt to their
their ability to modify environment. In this way,
certain elements of their they do not need to rely
habitat to their advantage. —_ on natural evolution alone.
‘e homeothermic—which means they are capable of maintaining a
rnal body temperature despite environmental conditions. This ability
wed them to establish themselves in every region of the
asis is achieved by a series of processes that tend
vels and concentrations of minerals and
» blood in equilibrium as well as
cumulation of waste
nong other things.
<
#
A Perfect System
Polar bears, like all mammals, keep their
internal temperature constant. These
bears tolerate the extreme cold of the Arctic
ice because they have developed a
sophisticated system to increase their ability to
isolate and capture sunlight. Their transparent
hair receives a large part of it and therefore
appears to be white. The hair transmits this
light inward, where there is a thick layer of
black skin, an efficient solar collector. Their fur
is made up of hollow hairs, approximately 6
inches (15 cm) long, which insulate the bear in
Great
Swisnthers
Polar bears swim with ease in open
waters and reach a speed of 6 miles an
hour (10:kim/h). They propel themselves
with their great front paws and use their
back feet as rudders. The bear's hair is hollow
= and filled.with air, which helps with buoyancy.
When the bear dives, its eyes remain open.
SHELTERED CU
The cubs are born in
winter, and the skin of
the mother generates
heat that protects the =
cubs fromthe ‘«&
extreme cold.
but also an energy
critical levels—at
il -75° F (-50° to
ases and begins to
rapidly burn energy from fat ood. In this way, the
polar bear maintains its ody temperature.
'~ Re 3
HAIR
RESPIRATORY An Hollow chamber
PATHWAYS impermeable, with air
The bears have translucent
membranes in their surface
snouts that warm and
humidify the air before
it reaches the lungs.
Outer
UNDERFUR
( }—- PRINCIPAL FAT
RESERVES
Thighs, haunches,
and abdomen
When they tire of swimming,
they rest, floating. They manage
to cross distances of over 37
miles (60 km) in this manner.
gin
ERT —
Forelimbs
function as
a motor.
HYDRODYNAMIC
low temperatures and keep the skin from —_— = ma
getting wet when in the water. "POLAR BEAR™ ANATOMY a4
- 7 nat = 5 ~ ~
— Be —" x - ein
= —— 3 ae te ed - = ~-2-t + 7
ENTRANCE
wre
nae ; -,
i " 4 é poly
eee ‘a F ‘ oD eT.
ee) lari oo "ect
wees Y a.
ie a
pee Ne hh = ay
Vey a
<
a iv
eh
ration
TRAVEL SOUTH, ESCAPING THE BREAKUP
OF THE ARCTIC ICE.
UNDER THE ICE
Females dig a tunnel in the
spring; when they become
pregnant, they hibernate SECONDARY
without eating and can lose ACCESS
45 percent of their weight. TUNNEL
je
CHAMBER
OR REFUGE
MAIN
ACCESS
TUNNEL
their extremities and
their tails over their bodies as a
of blanket. In this way, the surface
area subjected to heat loss will be
minimal. Hot-climate animals stretch out
their bodies to dissipate heat.
Their palms have surfaces
with small papillae that
create friction with ice,
keeping them from slipping.
f
What They Are Like
ll mammals have
stereoscopic vision, which
gives them depth perception.
Moreover, in the case of
hunters such as tigers, their
night vision is six times keener than
that of humans. There are many species
that have a very keen sense of smell,
and the sense of taste is closely linked
to that of smell. Hair, too, performs
Panthera tigris tigris is the largest
member of the feline family, easily
recognized by its orange fur with
black stripes and white spots.
various functions in these animals'
lives—conserving body heat, providing
protection, and serving as camouflage.
Those that have almost no hair and live
in environments where the
GRACE AND MOVEMENT DEVELOPED SENSES
EXTREMITIES SOFT CONTACT
WHAT DOESN'T RUN, FLIES
LOOKS THAT KILL
temperature is very low, such as whales,
have developed a layer of fat under their
skins.
20 WHAT THEY ARE LIKE
Grace and Movement
orses, one of the odd-toed, hoofed, ungulate mammals, are considered symbols of grace and
freedom. They have great vigor and can run swiftly because their spine bends very little,
preventing unnecessary expenditure of energy during the rising and falling of their body mass.
They are equipped with strong, light, and flexible bones, and their muscles work by contraction,
arranged in pairs or groups that pull in opposing directions. @
MAMMALS 21
ORBITAL > ATLAS AXIS
CAVITY First cervical vertebra Second cervical vertebra
is articulated, allowing the nape to allows lateral movement—necessary
bend up and down. for the horse to turn.
Atlas & a>
NASAL
CAVITY
VERTEBRAE
7 CERVICAL = >
FROM 17 T0 19 Correct position of \
DORSAL an equestrian
Normally there are :
18, but the number Axis
is often higher or
P t R lower.
ower to Run Skeleton
IFS) Horses are one of the most powerful mammals and achieve BUCCAL
Lali great speeds relative to their body mass. The natural purpose CAVITY
of their musculature is to allow them to flee their enemies. This 50R6LUMBAR 7 SACRAL 18 COCCYGEAL
—_ ability has allowed the species to survive for millions of years. Their eae
—— great energy is generated by contracting muscles. number of very
mobile vertebrae.
pices The medullary canal
Bone Endomysium Muscle fascicle in each maxillary Harrows.
(between fibers) aos bone, including: SCAPULA :
df tts a2 —Muscle fiber Tum
, eas |e” | 4 (cell) 3 molars
“7%! <*5 3 premolars L
— 6 incisors PELVIS
5 é 2 canines
a ie Wagtea Ischium —C)
go’ 782 as Perimysium
rae
\ i ; oe Blood Vessel
j \ rte STERNUM
VP STERNOCEPHALICUS Epinysiurn is the bone that er
{ | - ah) TENDONS joins the ribs in 7 @
= are lengths of connective tissue ie iy of the
e that secure one end of a muscle we sas OUrmng
(striated muscle tissue) to a bone Pain eage
(bone tissue). Ligaments connect a ee ing - HUMERUS
bones to one another. VISE Era SUP POnt
ULNA PATELLA
See, ace GALLOPING LEGS Tip of
FLEXOR The hind legs generate the impetus and the leap, the Tarsus
CAUDAL and the front legs bear the weight upon landing. To
DEEP PECTORAL \e EXTENSOR CARPI save energy, the spine hardly arches when running. FIBULA
MUSCLE \ " RADIALIS In felines, however, which are lighter, it does.
® COMMON DIGITAL TIBIA
_ 4 EXTENSOR EQUINE FOOT
Lateral Digital
Extensor ANNULAR Metacarpus ]
Twins LIGAMENTS Third Phalanx y
Second Phalanx a KNEE
Lateral Band 5
MPH Navicular Bone
Collateral DEEP DIGITAL (80KMH)
Ligament FLEXOR TENDON THE SPEED REACHED He oe
BY A RUNNING HORSE ee IS THE NUMBER
Plantar Pad METACARPUS —————* ) OF BONES IN
THE SKELETON :
OF A HORSE O————- METATARSUS
THE HORSE IN ACTION HOOF Heel (excluding the 7
Because they Bar —__——__ 4% tailbones)
have this kind of {
a “nail," horses are —- Frog PASTERN
called ungulates,
PHALANGES
ee en — $e —
as are tapirs and = Sole
rhinoceroses.
Horseshoe
MAMMALS 23
22 WHAT THEY ARE LIKE
FIRST
FINGER
Extremities
ammals' extremities are basically either of the foot or chiridium type but modified
according to the way in which each species moves about. Thus, for example, they become
fins for swimming in aquatic mammals and membranous wings in bats. In land mammals,
these variations depend on the way the animal bears its weight in walking: those that use the
whole foot are called plantigrades; those that place their weight on their digits, digitigrades; and
those that only touch the ground with the tips of their phalanges, ungulates. e
Chiroptera
From the Greek, meaning
“winged hand,” this is how bats
are designated because their
forelimbs are modified, the
fingers thinning and
lengthening to be able to
support a membrane that
functions as a wing. The hind
limbs did not change similarly:
they have claws.
SECOND
FINGER
THIRD
FINGER
FOURTH
FINGER
PATAGIUM
4 LEFT FOOT OF
Functionally Adapted CHIMPANZEE
Another criterion for classifying mammals by their legs, in addition ance METATARSAL ,
to their morphology, is the function the legs perform. Cats, dogs,
and horses have four limbs for locomotion. Primates have
differentiated forelimbs, and they also use legs to capture food or
bring it to their mouth. Others use legs to swim or fly.
KEY ’
ES Tibia/Fibula BIG TOE——© PHALAN)
Ma Tarsi
BE Metatars Cetaceans
Ma Phalanges Whales adapted so well to the sea
that they seem to be fish. But inside
their fins —modified front legs—
there is a bony structure similar to that
of a hand with fingers. They have no
hind limbs: the tail, placed horizontally
and used to move in the water, has no
connection to those limbs.
Tail
METATARSAL
» toes .
SCAPULA
UNGULIGRADE I UNGULIGRADE II Lies ip pie aaa WALK OR CLIMB CUNEIFORM BONES aa
HORSES GOATS : There is a fundamental differen HORIZONTAL IN
If you observe their The majority of ungulates, RUNNING SPECIES between the Bexnan foot and Fie. MAMMALS THAT ULNA
footprints, you will see such as goats, have an HAVE FEWER.
that only their hooves even number of toes. They Bt a rey ae ies mney eos ~~ SWIM, AS DISTINCT RADIUS
long, prehensile digit in its foot FROM FISH
are called artiodactyls as
opposed to perissodactyls,
leave marks. Horses'
hooves are made up of
similar to that in its hand. Monkeys
use their feet to grab branches as
EVOLUTION
It is thought that
Felines
only ne toe: elie they move through the trees. METACARPI ime
Chimpanzee Human CUBOID BONES The futon of ia ras is to PHALANGES marine ungulates,
support their agile and elastic whose spines
LYING FOOTPRINTS SCAPHOIE Say, bodies, allowing them to move alate up and
Other species of unguligrades (or simply ungulates) about. The front paws also help aie
can have more toes that make up their hooves, but in hunting to catch and hold prey.
they do not place weight on more than two of them.
ASTRAGALUS
RETRACTABLE NAIL
DIGITIGRADE PLANTIGRADE
DOG HUMAN NAIL ——————_p Phalanx ELASTIC LIGAMENT
These mammals place Primates, and of course When the tendon contracts,
HIPPOPOTAMUS
PIG CHEVROTAIN DEER
CAMEL
the full surface of
their toes (or some of
them) on the ground much of the sole of the
when walking. They foot when walking, piece itis
usually leave the mark particularly on the
of their front toes and
a small part of the
forefoot as a footprint.
Dogs and cats are the
best-known examples.
humans, bear their
weight on their toes and
metatarsus. Rats,
weasels, bears, rabbits,
skunks, raccoons, mice,
and hedgehogs are also
plantigrades.
DIGITAL PAD
this ligament retracts, and
then the nail does, too.
TENDON
24 WHAT THEY ARE LIKE MAMMALS 25
| : J
What Doesn't Run, Flies = on siherian
) f ie like Flyin
hey are meteors of flesh, bone, and hot blood. Cheetahs are the fastest of ee oy Squirre
the land animals and unique members of the Felidae family, which hunt 4 fede thse ahaa
using their keen vision and great speed. They can reach over 70 miles per TAKEOFF IN THE AIR LANDING as common squirrels, to which
hour (115 km/h) in short runs and reach 45 miles per hour (72 km/h) in an anes ee Seg eee
: ; L j pe TOES Fale :
average of only 2 seconds. They can get above 60 miles per hour (100 km/h), towatd ancitet ene cuban of san tek he aaa ng dus: before Fancang te lowers Upon landing, t grabs live in the mixed forests of
but they can sustain that speed for only a few seconds. They look like leopards jumps and stretches its legs. Thanks to legs, using the membrane pita Sessa ieee vie or lee Europe derass Sa
ri : aaa 7 4 u that it can glide from the top of one tree like an air brake. It lands its toes. and into East Asia.
although their physical characteristics are different: they are longer and to the trunk of another. very gently on all four paws.
thinner, and their heads are smaller and rounded. e@
NOSTRILS TAIL : SHOULDER HEAD
Cheetahs @ START ® SPINAL Very wide, they allow Large compared to EXTENDING Fi ¢ miles The extensive Small and
Whereas tigers prefer to lie in wait for Leek CONTRACTION it to ei HUTS a oe of the a THE SPINE per hour [eior of He sO
prey and then jump on it, the cheetah egins Ong Then it gathers its legs oxygen as It runs. It acts aS a pilvo Ina counterthrust opposing S oulder allows wi 4 OW alr
: a by lengthening A A used to suddenly the contraction, the spine d 15 km/h) it to take very resistance.
uses explosive speed of over 60 miles per : : under its body, contracting alee tend Fei d
hour (100 km/h) to run its prey down. le etiive and its cervical spine to the Slang: ditechon. sate tg A aged MAXIMUM SPEED, BUT CAN long leaps.
extending its maximum. can cover 26 feet (8 m) ina BE MAINTAINED FOR ONLY
four legs. single stride. 550 YARDS (500 M)
‘
Ae
LIMBS
Long and agile. It
has a powerful,
flexible skeleton
and musculature. |
SECOND POINT
OF CONTACT
Extending its four
Order Carnivora
Family Felidae legs again, it picks up
Epeeeecnene FIRST POINT OF CONTACT a Sloth
F supporting itself on
jubatus (Africa) As it runs, only one leg EP b a | y These animals are notable for their
Aciane touches the ground at a (18) GALS Wet Lye tremely sl tabolism. Th
cinonyx time, But during the aera ee metabolism. They f=
F : , take half a minute to move a f
venaticus (Asia) cervical contraction, the ZIGZAGGING limb! They are also somewhat
entire body lifts from the AT HIGH myopic, their hearing is
ground. SPEED mediocre, and their sense
PAWS of smell barely serves to
BIPEDS VERSUS mech DIGITS distinguish the plants
eetans Can A
QUADRUPEDS i make sharp turns 5 in the hands on which they teed.
while running at Aitken They are at the extreme
high speed. * opposite of cheetahs.
However, since they
: NAILS practically live perched in
ine easd trees, they do not need to
i move or see or hear precisely.
; 5 eee eae are Useanne their way of life.
18 MPH (29 KM/H) 23 MPH (37 KM/H) 42 MPH (67 KM/H) 50 MPH (80 KM/H) 70 MPH (115 KM/H) a eae nie allowing them
SIX-LINED RACERUNNER HUMAN BEING GREYHOUND HORSE CHEETAH ahatichestahe. to grip the
Cnemidophorus Track record: Asafa Powell (Jamaica), A dog witha light skeleton An anatomy designed for It only takes 2 seconds to reach a firmly grip the ground better. THREE-TOED SLOTH
Native to the Amazon River basin
sexlineatus 110 yards (100 m) in 9.77 seconds and aerodynamic anatomy — running, powerful musculature speed of 45 miles per hour (72 km/h). ground.
26 WHAT THEY ARE LIKE
Looks That Kill
igers are the largest of the world's felines. Predators par
excellence, they have physical skills and highly developed senses
that they use to hunt for prey. Their daytime vision is as good as
that of humans, except for a difficulty in seeing details. However, at
night, when tigers usually hunt, their vision is six times keener than that
of a human being, because tigers’ eyes have larger anterior chambers
and lenses and wider pupils.
Seeing Even in the Dark
Hunting animals depend on the keenness of their senses to detect their prey.
Felines can dilate their pupils up to three times more than humans, and they
see best when light is dim and their prey's movements are very subtle. A system
of 15 layers of cells forms a sort of mirror (tapetum lucidum) located behind the
retina or back of the eye. This mirror amplifies the light that enters and is also the
reason that the animal's eyes shine in the dark. At the same time, their eyes are
six times more sensitive to light than those of people. Tigers' nocturnal vision also
increases because of the great adaptability of their circular pupils when they are
completely open.
tt a1 yy 5 ae mp te
C Y AN¢ Y % i
|
ANS It PA Pg
Ay T Tw, (Me yo Tigers have a 255°
gh VEL ha) Yai } angle of vision, of
EI PFEL which 120° is
binocular, whereas
humans have 210° with
120° of it binocular.
FOCUS 2
gq 50 times
THE LIGHT AMPLIFICATION
CAPABILITY OF THE RETINA
OF FELINES
‘CONJUNCTIVA
CORNEA
BINOCULAR
VISION
Part of the field
of vision of one
eye overlaps that
of the other eye,
which makes
three-dimensional x2 = Ls a loo Foe She ee - s
vision possible. S a ; : : : Sas Je Thi re tia Sat Se : " 2 ‘ RETINA OF A
Hunters’ skills SZ Wz id DI ont hye aa ; Sse : — MOCTURNAL
depend on oa : : ; Poa xh : : genni ogee
binocular vision, SME A “b ‘ =a NRA -- 2 = Roe ht
because it allows . ¥ ap cy ZF , , o Fann ae A > Se x : ora ;
them to judge the aes, ee = ns Se : : ed
distance and size
of their prey.
PUPILS
They regulate the passage of light
to the retina by contracting in
bright light and dilating in the dark.
In each species of mammal, the
pupils have a distinctive shape.
, a Pa
CAT
RETINA
LIGHTS OR COLORS
The retina's
sensitivity to light
depends on rod-
Shaped cells, and
forms and colors
depend on other
Cells, which are
cone-shaped. In
tigers, the former
predominate.
DOG WITH LONG
SNOUT
28 WHAT THEY ARE LIKE MAMMALS 29
Sense of Smell
Their most developed sense; they have
220 million olfactory cells in their nasal
cavities. Mucous tissue, located in the
nasal conchae of the snout, warms and
moistens the air that they inhale.
covers these bones is
responsible for
secreting mucus that
traps inhaled particles.
Developed Senses The ett tat | :
ogs have inherited from wolves great hearing and an excellent sense of smell. Both perform
an essential role in their relationship to their surroundings and many of their social
activities. However, they are very dependent on the keenness of their senses depending on
the habitat in which they develop. Whereas humans often remember other people as images,
dogs do so with their sense of smell, their most important sense. They have 44 times more
. . . “ 4A 4
olfactory cells than people do, and they can perceive smells in an area covering some 24 / fy ie al
square inches (150 sq cm). Dogs can discern one molecule out of a million other ones, ft = Dendrites
and they can hear sounds so low that they are imperceptible to people. eee
ayer
Hearing INSIDE THE COCHLEA parent
The auditory ability of dogs is four times greater than that of ; ; rie -
human beings, and it is highly developed. Their ability depends pails — i
on the shape and orientation of their ears, which allow them to sas he AURICULAR
locate and pay closer attention to sounds, although this varies Organ CARTILAGE
by breed. They can hear sharper tones and much softer sounds, of Corti
and they can directly locate the spatial reference point where
a noise was produced. Dogs hear sounds of up to 40 kilohertz,
whereas the upper limit for human hearing is 18 kilohertz. Scala
Tympani
Nerve
/ Fiber
A
SEMICIRCULAR AUDITORY Over
CANALS NERVE
| 1 000 times
~ THE CAPABILITY OF A DOG'S SENSE
ee OF SMELL COMPARED TO THAT OF
INCUS (ANVIL) ee? heer
MALLEUS (HAMMER) , COCHLEAR @
STAPES (STIRRUP) NERVE f
COCHLEA Taste
-MIDDLE EAR
ane Dogs perceive the chemical substances that
foods are made of by means of receptor cells
found in the taste buds located at the back of
the tongue and in the soft part of the palate.
AUDITORY CANAL TASTE BUDS
TYMPANIC MEMBRANE
Dispersed throughout
the tongue. Complex
INTERNAL interactions among
STRUCTURE OF
them determine taste by
means of nerve endings.
The dome diverts
sounds toward the OVAL EUSTACHIAN
bulla, which sends WINDOW TUBE - TASTE
electric signalsto == ; L RECEPTORS THE TONGUE
the brain. Individual receptor AND TASTES
heed ed | Sweet tastes are
: information to the wee
AUDITORY LEVELS , olfactory centers of experienced in the
Ohertz 1 10 100 1,000 10,000 20,000 40,000 the brain. front part of the
People |! ! ! , cagitr:, & SOR tongue, sour ones
Foxes g = in the center, and
Mice yo we a g salty ones in the
Bats a 5 5 back. On either
Frogs i a a side salty and
Elephants 1 SSIET sweet are mixed.
Birds
|
30 WHAT THEY ARE LIKE MAMMALS 31
soft Contact
HAIR Diverse Hairs J WOOL FIBER
STRUCTURE . Protofibri] —-—————————
Nase The majority of mammals’ fur is BAT HAIR ; aoe
dmired, adored, and coveted by humans, a mammal's fur coat is much more than ee PIES UO CN ON FIVE ee see
a skin covering. It acts as a protective layer against mechanical injuries, prevents pple to a group of proteins called % Series ona
invasion by germs, and regulates the loss of body heat and moisture. In many co melanins. Each coat has different "¥ Cortex 90% —,
Medulla layers. Guard hairs are the first layer, .
species, such as the Arctic fox, it provides camouflage by changing color and texture
providing protection. Underneath
Cuticle 10%
. that, there is a fine layer called ENLARGED
from winter to summer. a underfur, formed by constantly = WooL
Scaly Cuticle growing short hairs that renew ra This is the
the coat. ate most complex
= natural textile
Sas or ; fiber in existence.
4 + 7 = It absorbs moisture
Fur and Mimicry The Skin = eres
Mammals from cold regions, such as
polar bears, have white fur to camouflage
EPIDERMIS ———_
themselves in snow. Others, such as polar, Outer layer POLAR PORCUPINE QUILLS
: A formed by BEAR HAIR =
or Arctic, foxes and the American hare, 3 : q lled d hairs, th
change their fur color with the seasons, resistant, flat | -_- a ae Bales guamu nalts ley ore
. g Antal ee act " cells DERMAL PAPILLA hairs is hollow and i ~ located outside the fur. In the case
seine ‘ hie anata cc attaches the De ean te =< of the porcupine, they have been
summer fur would make them easy prey. dermis to the insulating capability é — modified to form defensive quills.
Lions beige color el them avoid bang epidermis. of the inner layer. = 5 () 000
iscovered while they stalk their prey. g MERKEL'S DISK )
By Bese ee rn oe THE NUMBER OF QUILLS THAT
DERMIS = under the skin's a COVER A PORCUPINE (148 PER
Layer with blood F surface that = SQUARE INCH [23 PER SQ CMI)
vessels, glands, responds to light, 4
and nerve endings. continuous touch J
WINTER
Arctic foxes have two
kinds of color phases.
White phase foxes are
almost pure white in
It is a layer of
sebaceous glands
that secrete an
oily substance,
and pressure
Giacy ee
mide [i
Skin
~
Insulating
Insulation is one of the functions
O—————- Mini-quills
Sharp scales
teed sebum, on the SEBACEOUS of animals’ skins and hair. It not i \
camouflage themselves surface of the skin. GLAND only helps to conserve body
in the snow and ice. % secretes a waxy warmth but also, as in the case
3 substance, Ol of camels, protects them from
' sebum, which : excessive heat. Its color often
i moistens the skin, blends in with its surroundings,
¢ making it serving as camouflage. ERECTION
€ waterproof. MECHANISM
5 Base of ;
. > OUTER | When the quill
ry SUMMER ot PACINIAN ral touches a strange
a The fur coat of the ~ CORPUSCLE Epidermis surface, it exerts a
By Arctic'fox(Alopex. x, | light downward
/agopus) in summer is FATTY TISSUE ;? Sense receptors pressure on the
half as thick as that of This is a specialized A under the dermis. epidermis.
icy coq winter, with less than conjunctive tissue ¥ The Pacini receptors |
half the underfur. In
made up primarily of
lie under the layer
The fine tissue
sainale turn sary connective cells called of deep fat and Sue Se eal
4 brown to grayish color, adipocytes, which detect vibration and P breaks.
and those that have a store energy in the pressure. (
“plue” phase are
browner and darker.
form of triglycerides.
SWEAT GLANDS
When the body is hot, the glan¢
chs porate teal ocd secrete sweat, which passes LAYER OF FAT
EXCESSIVE UV RAYS. through the sweat ducts to the
GREY WOLF
«
surface of the skin.
’ Min,
The erector pili
muscle receives
the contact signal
and contracts.
EAT TO LIVE
34-35 44-45
36-37 46-47
38-39
40-41 50-51
42-43
48-49
52-53
54-55
56-57
58-59
34 BEHAVIOR AND LIFE CYCLE
Life Cycle
irth, maturity, reproduction, and death: this life cycle has
certain particularities among mammals. As a general rule,
the larger a mammal, the longer the members of its
species tend to live but the fewer offspring are born to a single
female per litter or reproductive season. Most mammals,
including humans, are placental mammals; their vital functions
are fully developed inside the body of the mother. @
90 Years
A WHALE'S AVERAGE LIFE SPAN—THE
GREATEST OF ANY LIVING MAMMAL
Placental Mammals They male Weaning
oe f natural
This is the largest group of mammals, the one that has are or dig 35 TO 40 DAYS XU
multiplied most on the planet, although its form of underground. Young rabbits remain with their Se al
gestation and lactation produces great wear and tear
on the females, making them less prolific. They are
generally polygenetic: a few males (the most
competitive) fertilize many females, and other
males, none. Only 3 percent of mammals are } . rr,
monogamous in each season. In these
cases, males participate in rearing the
offspring, as they also do when resources
are scarce. If resources are abundant,
the females take care of the young alone,
and the males mate with other females.
Maturity
5 TO 7 MONTHS
The better rabbits are fed,
the more quickly they become
capable of reproducing. They
are considered adults at 8 or
9 months, when they weigh
some 2 pounds (900 g).
mother even after nursing ends
for protection and the inculcation
of species-specific behavior.
They have
four to five
pairs of
breasts.
Lactation
25 TO 30 DAYS
fed upon milk, although
they can digest solid food
after 20 days. The young
abandon the burrow after
35 or 40 days and remain
in the area where they
were raised (philopatry).
Female
rabbits can
mate at
any time.
Longevity
4 to 10 years
Gestation
28 TO 33 DAYS EASTERN
They spend it in a collective ; COTTONTAIL
burrow (warren) duginthe == sem RABBIT
ground and covered with a. They are born mh ! oe
tati d fur. Th 4 inches \ | . floridanus
vegetation and fur. The 10 x » without fur, with
female will abandon it as (0 cm) oe 4 _) semitranslucent
soon as lactation ends. | = skin.
AT BIRTH
The young weigh
NUMBER OF OFFSPRING som ts 18)
ounces (40-50 g).
They do not open
their eyes until the
10th day.
Goat all all ail OFFSPRING 3 to 9
Young
Dog wf of of pf eee,
PER LITTER, AND
Rat EAE AEMRMR ME 610 FROM 5 TO 7
ARC A AR A A A OFFSPRING LITTERS PER YEAR
In general, it is inversely
proportional to the species' size.
Cow rr
1 OFFSPRING
/
+
\\ | /
\ ,
Marsupial Se |
arsupia Ss \ {| The young animal fastens itself to
its mother and is carried around
by her, clinging to her shoulders.
Very short gestation period, after :
which they develop in a sort of partially Y,
open pouch (the marsupium), which the
female carries on her belly. The majority
of the roughly 300 known species of
BANISHED
marsupials are solitary, except in mating OFFSPRING
periods. In general, they are promiscuous iain insane
animals, although some, such as wallabies the offspring and other Bie,
young males apart. x‘
(small kangaroos), tend to mate with the
same female all their life.
Dominant
males mate
with all the
females.
Lactation
22 WEEKS
A muscle inside the pouch
prevents the infant from
falling out. At 22 weeks,
it opens its eyes, anda
type of pap produced by
Some females
By the end of strong males.
lactation, fur
its mother is added to its croleily
diet, which will prepare it f
for an herbivorous diet. KOALA
Phascolarctos
cinereus
|
Gestation Gaieh
35 DAYS
With its extremities and
functional organs barely
developed at birth, the
newborn must crawl by itself
from the cloaca to the pouch
to continue its development.
1 offspring
1 BIRTH PER YEAR
GESTATION PERIODS Monotremes In the Pouch
balun ONT HS Mammals whose females lay eggs are generally 2 TO 3 MONTHS
Elephants solitary species for most of the year. Platypuses After breaking the shell, the
| are seen as couples only when they mate.
Although they have a period of courtship for
one to three months, the males have no
| relationship with the females after
copulation or with the offspring. Short-
beaked echidna females practice
polyandry, copulating with various
males in various seasons.
young are suckled while they
remain in a kind of pouch of
Giraffes the female.
Gibbons
I
ae
I
Dogs
i ox
COMPARISON
OF EGG SIZE
The shell is soft
and facilitates the
offspring's birth.
Unlike birds, they
do not have beaks.
Undeveloped
Newborn Limbs
Offspring
Incubation
12 DAYS
Eggs gestate for a month t
before hatching. They
incubate within a pouch
for about 10 days to
remain at the proper
temperature until the
young are born.
Chicken
ae .
Echidna ..: inch 1to3
leave to look for \,
MAMMALS 35
Leaving the Pouch
1 YEAR
The offspring reaches a size that allows it
to fend for itself. It has already
incorporated herbivorous food into its
diet. The mother can become pregnant
again, but its young will remain nearby.
Sexual
Maturity
3 TO 4 YEARS
_At two years, koalas
~~ valready have developed
sexual organs (females
earlier than males). But
, they do not start
mating until one or two
years later.
LONGEVITY
People 70 years
Elephants 70
Horses 40
Giraffes 20
Cats 15
Longevity Dogs 15
15 to 20 years
Hamsters 3
Underground cave or
a cave among rocks
The fur is .
already spiny. Weaning
4 TO 6 MONTHS
After three months,
the offspring can leave
the burrow or remain
in it alone for up toa
day and a half before
finally separating from
the mother.
Longevity
50 years
SHORT-BEAKED
ECHIDNA
Tachyglossus
aculeatus
=
auty and Height», SS 2. ) Ae.
Dermis Fibrous tissue
, that protects - ‘ x Near the end of
Sat: # a female with whom.to mate is the great rs oe summer, stags display
. — i their new antlers,
effort of the male's life, a competition with other —
ales of his own species. Each animal-has-its»
ticular nuances. For stags, antlers play a fundamental
1 Winning the heart of their chosen one. Whichever
which will be larger
and heavier than the
previous ones.
Fe: stag has the most beautiful, longest, and sharpest horns
~~ will be the winner. Thus, he will be able to defend his
=. territory, court the female, and reproduce.
Horns are shed every
. year. Animals between
' the ages of 6 and 10
display the finest
antlers.
Stags rub their antlers
against-trees.and bushes
to get rid of the
membrane that covers
them.
2
New antlers are covered
with a fine membrane,
called velvet, that will
stay on the horns until
they are fully developed.
<— 1
/ At the onset of
’ autumn, stags begin
to lose their antlers,
which will be
replaced by new ones.
Antlers
FORK PALM
Fights
Red Deer When two males fight over a harem,
IR These are svelte, robust, well- each will display his antlers to
Le@ formed animals with a majestic frighten his rival. The horns can also
and haughty carriage. They are very be used to defend against predators.
timid and fearful, and it is thought that
the species is 400,000 years old. They
are active at daybreak and evening,
and males usually live alone. Females A\W \ - ray} oe = PEDICLE
d d in herds. ; r
i crn —— porns and Antlers Bellows
4 7 : outgrowths of the cranium, Sonorous and discordant, they begin
Opin oiagecctvia noe 31 inches covered by ategument that forms a sheath. to be heard when spring arrives,
Family Cervidae ia (80 cm) _ They appear in bovids of both sexes and are announcing the beginning of rut, or mating
generally permanent. Antlers are also season. They not only attempt to keep
a extensions of the cranium; they are limited competitors away with their call but they
Diet Herbivorous to the deer family, are present only in males, _ also use the sound to attract unattached
Species Cervus elaphus
Weight 400 pounds and are replaced annually. females to join the male's herd.
(male) (180 kg)
is
> . > ra
a J ‘
38 BEHAVIOR AND LIFE CYCLE ee. * ne O44 . MAMMALS 39
i, — a
.
Oviparous Mammals LN eine
* For reproduction, the female
or a mammal to lay eggs seems improbable, but the surprising dite: makes a deep burrow, where it
monotreme females, instead of giving birth to young, are oviparous. Ne dys tape ee ee
‘ a ‘ , Oh Sty : iniShes digging the burrow.
They are warm-blooded, have hair, and feed their newborn through ) Ae teva TBS Geb Pen Shh Son
mammary glands despite having no nipples. Platypuses seem like a ty oe yee PLR ges / Rep roductive: =
cocktail of nature, inasmuch as parts of their bodies resemble those of ‘ do PANT EE 1 ce SYS Fuse Aycle: 3 a sel :
other types of animal. The other monotremes, echidnas, are covered SO 48 i, Cpe EE [fe he ae ; mse 2
2 é : . é a's “OF a va “ jtaig ie platypus. hasithree” réproductive cycles atu 7
with spines, and their young grow in the mother's pouch. arf ALIA ED ee 2 BL "—_‘and/spenitl lost of the year in solitude, Platypusest,
igs if PEF GE LBs “are seen aS couples‘only whensthey mate. aTheychave.a ta —=
OS het Te S/ ie + Peridtl of courtship before copulation, whichis =" ~"-» — a
Fg ¢: SL Lye performed by.a juxtaposition Of cloacae, THEI va > .. The eggs are covered by
gt Pusge DHE fs © Show © reproductive tate i is low sincethewlay only one,to” —- 7? a soft shell, and incubation
toh ay ey Ae * three éggs. The female platypus digs a buwow > lasts two weeks.
C gtts. kA - before laying her eggs, wheréas:echidnas haye a
72 ~ Z pouctrin which they incubate their young. s*
™ Combining the skin of a mole, the tail of a beaver, the feet z = = f - Unlike the hair on the other parts of its
of a frog, and the beak of a duck, platypuses are Soe ’ ~body, the hair in the echidna's > %
semiaquatic mammals endemic to the eastern part of Australia . g 2 a > pouch is soft.
and to the island of Tasmania. They construct burrows in Z .
riverbanks consisting of a long passageway. a .
Family Ornithorhynchidae = ~
Species Ornithorhynchus | !
anatinus —— 16 TO 24 INCHES — . =
- - (40-60 CM) ~ .
Diet Herbivorous ~~ ~
Weight 5.5 pounds (2.5 kg) 3 5 4
After 16 weeks, the young The mother has no nipples,
begin to feed on ants and but milk comes out through
ther small insects. = pores in her abdomen, from
— which the offspring si
HAIR
EYES The sharp spines
are kept closed originate within the fur.
The egg is the size of a
Cycle iq ™:
grape and stays at the
bottom of the female's
ncubating pouch. It
underwater. a s 11 days to hatch.
1/3 inch '
BILL SNOUT (9 mm)
has sensitive pret . iti
eer a een Rae search for and W/L A Mog” Be cre att inc on
electroreceptors that — e | Lives in Australia, New Guinea, and Tasmania. It catch food. Wie front feet uh
can perceive the electric | has an elongated snout in the form of a beak, no hold on to the
field generated by the teeth, and a long, retractable tongue. It is a notable RETRACTABLE mother's pouch,
muscles of their prey. digger and hibernates underground. Echidnas can live up TONGUE where it crawls in
to 50 years, and their hair varies according to the species. A sticky substance search of food.
on the long and
Family Tachyglossidae slender tongue
Seventy days
~ 2 . later it will leave
Species = Tachyglossus aculeatus ,* } allows it to catch "
: si NN termites and ants. LIMBS dee
pra have claws at the tips mother will place
of their feet, which help it wd a alba
where she wi
in digging rapidly.
' ! feed it for three
—_12 TO 35 INCHES — more months.
(30 TO 90 CM)
40 BEHAVIOR AND LIFE CYCLE
Efficient Nursery
\\ | arsupial females carry their newborn offspring in their marsupium, a pouch
attached to their belly. The offspring are not very well developed when they come
l into the world after a gestation period that varies from two to five weeks. Upon
emerging, the offspring must immediately climb with their front paws to the marsupium
to survive. Once inside, they will be protected. They are continually supplied with milk
through their mother's four teats, helping them complete their growth before leaving the
pouch for the outside world. ¢
Red Kangaroos PRODUC
ip Kangaroos are a family comprising several groups, including
great wallabies and tree-dwelling kangaroos. Kangaroos, the
prototypical marsupial, live in Australia and in Papua New Guinea,
never more than 9 miles (15 km) from water. They have large, muscular . oO a SSS
hind legs that they use to take great consecutive leaps, reaching speeds i H
of 15 to 20 miles per hour (24-32 km/h). They are able to maintain 2 days! |236 days 238 days
their balance standing only on their hind legs. Their hee! bone RUT AND NEW! iTHE OFFSPRING =| RUT AND NEW
(calcaneus) is long and acts as a lever. CONCEPTION! Ge NeDENE i CONCEPTION
Family Macropodidae
Species Macropus rufus
The female can
give birth to an
offspring while
-— another one is in
aa .. the marsupium.
:)
Females
are half
this size.
dibads 1 When preparing for the birth of an
offspring, the female kangaroo licks its coat
to form a kind of path some 5.5 inches (14
TEAT cm) long, which the offspring will follow to
grows in reach the entrance to the pouch located
tandem with the higher up on the belly.
offspring and
can reach 4
inches (10 cm)
long. Then it
contracts again.
2 Small kangaroos are born after a
few weeks of gestation in an early
stage of their development,
weighing less than 0.2 ounce (5 g).
They cannot see or hear. They only
move their front paws, with which
they drag themselves, following
their mother's trail of saliva and
guided by their sense of smell.
Two
UTERUSES
The marsupial
female has two
uteruses.
The baby kangaroo must \
get to the pouch within
three minutes or it will
not survive.
sc gy Lact 0.8 inch
At eight months, the Upon reaching the marsupium, the baby
offspring leaves the pouch fastens its mouth upon one of the four teats (2 0 mm)
and begins to add grass to inside. At this point, the baby is red and
its diet, but it will looks very fragile. However, it will grow THE SIZE OF AN OFFSPRING WHEN
continue to be suckled continuously over the next four months, IT ENTERS THE MARSUPIUM
until it is 18 months old. during which it will not leave the pouch.
42 BEHAVIOR AND LIFE CYCLE
Miraculous Placenta
he largest reproductive group is formed by placental
mammals, in which the unborn offspring develop in the
| female's uterus. During gestation, food and oxygen pass
from the mother to the fetus through an organ known as the
placenta, which allows the exchange of substances
through the blood. At birth, the offspring often
have no hair, are deaf and blind, and feed on
milk secreted by the female's mammary
glands, which become active after birth. e
Gestation of Rats
5 Gestation lasts between 22 and
a 24 days. Whereas the placenta
is discoid and hemochorial, the
ovaries are essential for
maintaining gestation. If an
ovariectomy is performed at any
stage of gestation, it will always
bring about a miscarriage or the
reabsorption of the fetuses since
the placenta does not produce
sufficient progesterone to maintain
gestation. The growth of the uterine
horns becomes visible on the thirteenth
day of gestation.
f composed of four cells and
\ | is covered with a thin layer
. § of glycoprotein. It implants
itself in the uterus.
The blastocyst has now
implanted and established
itself in the uterus. The fetus
begins to form, and the
blastocyst becomes a yolk sac.
EYE
begins to
develop and q BRAIN
can now be The brain is
observed. forming; it appears
ica transparent.
The embryo has now
fastened itself to the
embryonic sac (a sort of
balloon that covers the
fetus) and to the placenta.
The brain, eyes, and legs
begin to form.
2%
il
At this point, the embryo is
l y )
Rat embryo at the two-cell
stage. By the second day, it
will have four cells, and on
the third day, it will enter
the uterus.
ORGANS
Internal organs
begin to form and
become visible.
Placenta
From whales to shrews, placental mammals are
characterized by gestating their young inside the mother
and giving birth when they are well developed. To do so,
they have a special organ, the placenta. This is a spongy
tissue that completely surrounds the embryo, allowing
the exchange of substances through the blood. In this
way, the mother can transfer nutrients and oxygen to
the embryo, at the same time that she absorbs the
metabolic waste of her future offspring. After birth, the
placenta is immediately devoured by the mother, who
uses her teeth to help the young leave the structure.
EYELIDS
They grow very
rapidly, and by day
18 the eyes are
already covered.
TOES
Toes on the front
limbs can also be
distinguished.
MAMMALS 43
SPINE
The spine can be
distinguished and
is ready to support
the little rat.
ORGANS
The organs are now
almost complete
and ready to go out
into the world.
0.4 inch
@o mm)
Eyes and extremities are
now visible, and the
internal organs begin to
develop. A pre-cartilaginous Extremities are
maxillary and the outer ear in the process of
begin to form. formation.
SPINE
Cervical and lower
lumbar vertebrae
begin to develop.
LEGS
PLACENTA
The fetus is attached
to the placenta.
The eyelids grow very
rapidly, and within a few
hours the eyes will be
completely covered. The
palate has already
completed its development,
and the umbilical cord
retracts.
Only a few days are left
before the female will
give birth to a new litter
of little rats. At birth,
they are helpless despite
the fact that all their
organs are developed.
44 BEHAVIOR AND LIFE CYCLE
The First Days
ammals whose offspring develop within the uterus devote a lot of attention to their young
compared to other animals, because their pups are unable to live on their own at birth. That
is why they are cleaned, fed, and warmed. Dogs have various developmental stages. First is
the neonatal stage, which lasts from the opening of the pups' eyes until
they begin to hear. Then comes the socialization stage, which
runs from days 21 to 70, and, finally, the juvenile stage,
from 70 days on.
= ee , j
tion Period
This period is essential in the reproductive process
of mammals. The young of most placental
mammals are totally dependent in the first stages
of their life on mammary milk secretion.
YEARS
4. 3-4
years
34
24 18 18
months months
7-10
14 months i
v
Lion
Dog
ise) = cy
= = Se
= =. nc
3& eS ta
a BS)
o
Like humans, dogs develop slowly
after birth, because they are not fully
developed when they come into this
world and are incapable of living on
their own. They need a structured
environment in which they are cared for by
their parents and other members of the pack.
The first pup is born WET HAIR
between 1 and 2 Once dry, pups seek ¢
hours after a teat from which to
contractions \ suck colostrum,
begin. , en, "=" which consists of, 1
— 2s ~ among other things,
Ss immunological
, = substances.
-
‘
MEMBRANE
Placenta, which
covers the pup
~
-
at,
we > 7
**
LS
Sy 4
a Cf of
LA
The mother builds a
den in a warm place
away from noise.
At 20 days, pups
start to hear and
‘ react to sound.
This period, in which pups depend totally on the
mother, lasts from birth to 15 or 20 days, when
the pups open their eyes. But until then, they are
completely dependent on their mother, seek
contact with the mammary glands, and whimper
if they are alone. They have little ability to keep
themselves warm, and they even need the
stimulation of their mother to pass
body wastes.
EYES
remain shut
until the
second or
third week.
TACTILE Xx
They push with
their snout until
they are hidden. .
EXTENSOR REFLEX ;
At 12 days, pups
extend their hind legs
when picked up.
bo
The relationships of pups to
their mother and siblings are
essential to dogs' later
development, because,
although their social
structures and relationships
are largely innate, they must
be shaped, tested, and
practiced to develop properly.
Natural weaning involves offering pups
predigested food as a replacement for milk. When
the mother comes back from hunting, its mouth
has an odor, and the pups, stimulated by the odor,
smell her, lick her snout, rub it, and nibble her
jaws and face, which stimulates the regurgitation
of food. At this stage, in which the pups have milk
teeth, they can begin to eat these foods.
The mother lies
down to make it
easier for the pups
to reach her.
MAMMALS 45
Op —— SKIN
Short and
soft hair
Pups
At birth, pups do not innately
recognize members of their species;
they do not seem to know that they
are dogs. They must learn this, and
the mother and the rest of the litter
are in charge of teaching them this.
TRANSPORT
To move her weak pups, which cannot yet
walk, the mother picks them up by the skin on
the napes of their necks and places them in
the den. Fifteen days after birth, mother dogs
experience what is called the bonding
phenomenon: they become aware of the
litter's existence, see them as a group, and
notice if any puppy is missing.
The mother
moves the
pups without
hurting them.
STANDING UP
The mother no longer
needs to lie down and
is free to move away.
STRENGTH
The pups are
now able to be
on their own.
«7
46 BEHAVIOR AND LIFE CYCLE
Trademark
he exclusive characteristic of mammals, the one that immediately identifies them, is the
presence of milk-producing glands with which the females of all mammalian species feed
their offspring after they are born. The number and arrangement of mammary glands
vary by species. Teats are arranged in pairs and are present in both sexes, although only females
possess functional mammary glands—and that only while lactation lasts.
How a Cow Gives Milk pageant
GLANDS IN FEMALE MAMMALS
First impulse: This impulse is The brain gives PIG DOG ry \
With suction, the transmitted by off oxytocin, JZ . Ka =A
neurohormonal the inguinal nerve sending a signal to , v wy r Ww
reflex related to lactation tothe spinal cord and the heart through a branch iy A \ /
generates a nerve impulse. from there to the brain. —_ of the jugular vein. | )
J
Brain Pr 6 iS \ .
P i)
.SHEEP / \ 2 HORSE / )
— Inguinal ify 4)) é\ 6
Nerve } 4
} 4 |
\ 4
- rt! \
Bone Structure PO ay
(posterior view)
=a Milk ejection in The hormone is ,
the udder is distributed to :
produced by the the entire body ’
contraction of through the arterial , Suspensory
myoepithelial cells, system. This is how it \ Ligaments
which constrict the reaches the heart and ro
alveoli. then the udder.
Abdominal
Wall Muscle
Udder “i Mammary
Cows and mares have two . tymphiNode
mammary glands that mh =
together form an udder. It Pree
begins to function after |
birth and stops when the
offspring stop nursing. It
is regulated by pituitary, RIGHT
thyroid, placental, and FRONT -
adrenocortical hormones. QUARTER ,
’ Mammary J
Parenchyma ie
GALLONS (15 L)
OF MILK CAN BE
STORED IN THE
BOVINE UDDER.
LEFT REAR
QUARTER 4 ]
e<) om
‘ee
that drain into
a common duct
og SECONDARY
GLANDULAR
DUCTS
PRIMARY
Milk circulates , GLAND DUCTS
through this duct a
from the lobules
to the teat cistern.
SPHINCTER
MUSCLE
TEAT DUCT id
Alveolus
The functional unit
of milk production
BLOOD
CAPILLARIES
INTERNAL
CAVITY
(LUMEN)
Milk secretion
is stored here.
MILK DUCT
MYOEPITHELIAL
CELLS
COMPOSITION OF MILK (%)
PROTEINS CASEIN FAT
When the ducts
contract in response to
the oxytocin hormone
(the ejection, or let-
down, reflex), milk flows
” through the lactiferous
ducts to the mammary
gland's cistern.
CARBOHY- RESIDUES
DRATES
Human 1.2 05 38 70 0.2
Horse 2.2 13 17 6.2 0.5
Cow 3.5 2.8 3.7 4.8 0.7
Buffalo 4.0 350-15 48 0.7
Goat 3.6 2:f Ad 47 0.8
Sheep 5.8 49 79 45 0.8
ad =
NORMAL STATE
BEHAVIOR AND LIFE CYCLE
Development and Growth
lay is much more than entertainment for young mammals. This activity, which may appear
to have no specific purpose, is the way in which they learn to be part of their species in the
early stages of their lives, simultaneously acquiring the basic means of survival. In their
games, chimpanzees perform primary instinctive activities that, with time and improvement, will
become perfected instinctive activities. These include using tools, balancing in trees, and forming
communication. Young chimpanzees express themselves by means of sounds, facial gestures, and
body postures they imitate from adults. Play also allows them to develop their muscle strength
and achieve good motor coordination.
are emitted by chimpanzees,
including its pant-hoot: screams
and grunts that can be heard a
mile and a quarter (2 km) away.
Pant-hoots are unique to the This expression This expression —_ This gesture
individual and can help to identify communicates transmits indicates
terror. submission. worry.
each member of the group.
Play also functions as a method
of learning to survive in a wild
habitat. It trains carnivores in
hunting techniques and
herbivores in detecting, and
fleeing from, danger.
MAMMALS
Chimpanzees are characterized by their long arms,
which are endowed with great strength, and by
their opposable thumbs. The digits of their hands 4
and feet are large, allowing them to climb with
great ease. They can hold onto a branch with their
foot while they pluck its fruit with their hand.
Opposable
Thumb
When they move around ite
on all fours, they bear OG
their weight on the soles ,
of the feet and the
knuckles of their hands.
The use of tools is not common in mammals. However,
chimpanzees are capable of using objects as tools, a skill
they acquire by observing adults. They can use sticks to
eat termites or use leaves as spoons to drink water.
Some mammals, especially chimpanzees, communicate
through facial expressions. This ability is well developed
in the young primates, which express fear, submission,
and worry, among other feelings.
THEY CAN LEARN AND
EXPRESS WORDS USING
SIGN LANGUAGE.
What we humans call play appears to be
limited only to mammals, because they have
well-developed senses, intelligence, and the
ability to learn. It is through play that
mammals carry out their learning.
They have sensory
abilities very similar to “~~
those of people, and {
they distinguish smells
better. Because of
their large brains, they
are very intelligent
and can communicate
with people by signs.
Play also helps encourage apes to identify
with their species. It provides a basis for
learning to communicate through the use
of sounds and body posture to express,
for example, submission or domination.
A chimpanzee
pokes a stump
in search of
termites, using a
stick as a tool.
Only 15 minutes of play
with peers per day will
moderate the effects of
social isolation.
A great entertainment for apes
is hanging from trees. This
exercise improves their
coordination and arm strength.
BEHAVIOR AND LIFE CYCLE
Of Flesh Thou Art a
MAMMALS 5
Family Felidae Size a=
Species Panthera leo female?
Weight 265-410 pounds The bulk of their diet
(120-185 kg) consists of large mammals,
although they also catch
small mammals, birds, or
he carnivore group is composed of species & _
whose diet is based on hunting other 7 of *
animals. The kind of teeth they have help ri ~
them efficiently cut and tear the flesh of their 7 os
captured prey. Lions, the most sociable of the
felines, have good vision and sharp hearing;
they live in packs, and when they go
hunting, they do so as a group.
~
-
a
to
Lions
are characterized by a strong, muscular
physique. A male requires 15.5 pounds of meat
(7 kg) a day, whereas a female needs 11 pounds (5 ‘
kg). They have a short digestive tract, which rapidly
absorbs nutrients from the ingested meat.
UPPER PER
..__ PREMOLARS SANINE |
eT fT.
eo
_
re UPPER
4 INCISORS
«
The Hunt
LYING IN
AMBUSH
Hidden in the grass, the
lioness silently approaches
the prey. Other females wait
CARNASSIAL : in hiding.
MOLAR ;
They, arevery large; and the
dental crowns are-two,long
blades arranged as shears
that fit into’each other.
Together they slice and cut
flesh to perfection.
LOWER
INCISORS
ANTERIOR
PREMOLARS
y
CREF
Rubi ti
reptiles when the BUFFALO
opportunity arises. They are
not scavengers. They
generally eat only fresh
meat, something they have
killed or succeeded in taking
away from another predator.
Short, with a uniform
brown color. They
have an off-white tuft
of hair on the chin.
Their vision is six times
better than that of
humans. They also have
binocular vision, essential
for locating prey.
Measures some 35 inches
(90 cm) in length and allows
: ‘s them to keep their balance
while running. They also use
it to shoo away flies.
AQ Peis
OF MEAT CAN BE EATEN BY : |
A LION IN A SINGLE MEAL. i
Se
2 .
VLETHAL BITEage
W the prey falls, and the
lioness sinks her fangs into
the neck until she kills it.
The other females approach.
a”
ACCELERATION
When only a few yards away, it
starts running to catch the
zebra. It exceeds 30 miles per.
hour,(50 km/h); and the’other
lionesses cooperate inthe hunt.
The lioness hurls the weight of her
body-on the-zebra's neck, trying
to knock it down; if she succeeds,
the hunt will be successful.
Sy mS a a)
. ;
i
52 BEHAVIOR AND LIFE CYCLE MAMMALS 53
NB
The rumen creates an
environment appropriate for
the growth and reproduction of
microbes. The absence of
oxygen inside it favors the
growth of bacteria that can
digest plant cell walls to produce
simple sugars (glucose). Microbes
ferment glucose and provide energy
to grow and produce volatile fatty
acids as the final product of fermentation.
Herbivores
uminants, such as cows, sheep, or deer,
have stomachs made of four chambers with
which they carry out a unique kind of digestion.
Because these animals need to eat large quantities of
grass in very short times—or else be easy targets for
predators!—they have developed a digestive system that
allows them to swallow food, store it, and then return it
to the mouth to chew calmly. When animals carry out
this activity, they are said to ruminate.
Only small particles reach
the omasum, the third
stomach. Many are recycled
and absorbed as nutrients.
Filter inside the
omasum
KEY rumen produce amino acids, the
building blocks of proteins.
RUMEN F ;
: As they grow, microbes in the
: -
mama INGESTION AND mam ACID DIGESTION
FERMENTATION Bacteria can make use of
mam DIGESTION AND } j ammonia or urea as sources of
RUMINATION ABSORPTION RETICULUM ‘ | nitrogen to produce amino acids.
’ Without bacterial transformation,
mame REABSORPTION FERMENTATION SMALL ammonia and urea would be of no
OF NUTRIENTS AND DIGESTION
INTESTINE use to cows.
Teeth
Herbivorous animals such as horses and bovids
have molars with a large flat surface that reduces
food to pulp, as well as incisors for cutting grass.
Grinding is also done by the molars. When cows feel satiated,
Cows wrap Then they chew they regurgitate balls of
their tongues it with lateral food from the rumen and
around the food. movements.
chew them again in the ABOMASUM
ENAMEL ; mouth. This is called
rumination; it stimulates
salivation, and, as digestion is a
ia very slow process, cows make
use of rumination to improve
ROOT their own digestion together
: with the intervention of
| Cows lightly chew grass and anaerobic microorganisms such
ingest it into their first two as protozoa, bacteria, and fungi.
stomachs: the rumen and the
reticulum. Food passes continually
from the rumen to the reticulum
(nearly once every minute). There
various bacteria colonies begin
fermenting the food.
CEMENT -———-O
DENTINE ——————o
PULP. ————a
After the main process of
digestion and absorption
of nutrients, what remains
continues through the
small and large intestines.
There the remaining
digestive products
ferment, and wastes, or
feces, are formed.
INCISORS
The abomasum secretes strong
acids and digestive enzymes that
finish breaking down the food
bolus (the mass of chewed food).
helps ruminants reduce the size of the process that allows them to obtain energy
ingested food particles. It is part of the from plant cell walls, also called fiber.
@ om Db C D
REGURGITATION REMASTICATION REINSALIVATION REINGESTION
54 BEHAVIOR AND LIFE CYCLE
The Great Chain
WOLF
eats prey that it catches
but can also compete
|
Large carnivores are at
aintaining ecological balance requires the existence of heen cen with scavenger birds.
prey and predators. Predatorial species bring about a chain—there are no other
| V I sustained reduction in the number of individuals of the ee cde
prey species. If predators did not exist, their prey would probably
proliferate until the ecosystem collapsed, because there would SMALL-
not be enough food for them all. Disappearance of predators is pele arenes \y GEOR FROY'S CAT
the cause of many imbalances created in certain habitats by large felines and dogs, it is in likes to hunt larger
danger of extinction as a
result of human activity.
animals (such as deer).
people, whose predatory ability exceeds that of any other living
species. Like all other animal species, mammals do not make
up a food chain in themselves, instead depending at all
times on the participation of plants and other animals.
Small Omnivores
Equilibrium of the System
13
There is a very efficient natural equilibrium in the food chains of a Small carnivores feed on small, aise pe Hit ane Not Only Mammals
A as é é » amphibians, as well as on other Ferrets are important in
terrestrial ecosystem, of which mammals form various parts. For herbivorous mammals or on birds, : p
: meets i z mammals, such as rats, mice, controlling rodents, but i
this balance to be maintained, there can never be more herbivores than fish, or invertebrates. At the same and moles. They also eat fruit gi " ‘
plant food or enough carnivores to overwhelm the herbivores. If there time, they must be on guard : ‘ they must simultaneously
were more herbivores than plant food, they would eat all the vegetation against other, larger species. guard against birds of prey.
and then suffer a drastic population reduction. A similar situation would
occur if there were enough carnivores to overwhelm the herbivores.
Kings of the Jungle
Lions are great carnivores (one of the
largest in size) and strong, with little or no
competition. Cheetahs will rapidly flee
from lions if the latter arrive to challenge
them for their food. Only when a lion is
alone might a pack of hyenas, for example,
confront it to steal its meal.
Energy is transferred from one level to another in an ecosystem. At
each level, a small amount of energy is lost. What is retained at one
level is the potential energy that will be used by the next. Biomass is
the total mass of living matter; it can apply to a specific level of the
trophic pyramid, a population of individuals of the same species, or a
community of different species.
A J
Tertiary 4 a Si, “Ail
Consumers Energy aoe vf) \% \
Consumed Competition i ~s \ ul iE
pas : | Super-adapted
Secondary Within the same level, different Rerause’se their hich CHEETAH GAZELLE
Consumers herbivorous rodents (such as varied plant diet Pee P,
rats and prairie dogs) compete d rn il h ak ra
Primary i with each other for food. fo a SUSU TY AVE: 110: = —— f = 3
Consumers L problem surviving. z - LO OF Pu
Varied Diets ff ms Te |
: : J lf
sn wp ig Sees ‘a
ii algae), because they depend on ey the chain branches out. CAPE
them for subsistence. And other ‘ BUFFALO
mammals feed on them. ie lee »
= AN) “4
fi 4 —— 7 {
WM @
ZEBRA
Scavengers
Level 1
Because of photosynthesis, only plants
and algae can transform inorganic
matter into organic matter. They form
the beginning of the food chain.
eat meat from animals that
are already dead. Some
carnivores become scavengers
under conditions of scarcity.
MAMMALS 57
Th t dani
Brey Ae) Record the When a predator is detected, the lookout warns its group
one that kills the greatest so that all of them can take cover in a nearby hole. This
number of meerkats role rotates among different members of the group, and
the warning is given by a very wide repertoire of sounds,
each of which has a distinct meaning.
.
—-_ - Binocular and in
color, it allows
ee
It is common to see
them to locate ( :
their greatest them in the highest
prdaiors: birds places of their
territory on rocks or
c
3 rCiz c
OFFSPRING
Vein he father or
mothe Standing watch
gives the Cry nger, all
Merun to hide rr IW.
defend their territory
and stand watch: The"
iy dominant male is the
- reproducer.
ineacicts useit =
1 toBalancess “= ;
The meerkats' largest t: iF ‘
predator. To detect Oia theta in 8 ~*~
before it is!€en is of f tuple os! tion.
- ~*~
bad .
58 BEHAVIOR AND LIFE CYCLE
plays an important role,
allowing wolves to
Wolves =
in So ciety ri oats
b
ocial units and mutual aid are common in
mammals’ lives, except for a few species that live alone
or in small families. Wolves are social animals that live closely
attached to a group—the pack—that forms the basis of their social
structure. Behavior in a pack is highly regulated and hierarchical.
a .
There are two hierarchies in the pack: one
of males and another of females. At the top
of each are the alpha (or dominant) male
and female. Underneath this pair is a group
of subdominant wolves among whom there
may be little or no difference in rank.
Among females, a strong dominant-
submissive relationship is observed
between beta and gamma wolves, as well
as of the alpha female over those two.
oa” i
Made up of the breeding pair,
which is dominant, and their
descendants. Only the breeding
pair, however, are permanently
dominant. A relationship of
dominance-submission
between sexes is also
established. The alpha female
exercises clear dominance
over the subdominant males.
The highest-ranking adults live in
the central area or home. The
territory proper lies in the periphery
and is inhabited by subadults and
members of lower social rank.
Between these two areas is that of
vital domain, an intermediate area
inhabited by all members. The
territory can extend over 100
square miles (300 square km).
is inhabited by
the highest-
ranking animals.
is inhabited by
wolves of lower
social rank.
is inhabited
indiscriminately
by all the wolves.
This posture implies
submission and
nonaggression.
Fights and confrontations within the pack are
rituals by means of which relations of power and
hierarchical status are established and delimited.
Low-ranking
High-ranking
Tt crouches in front of the snout of
the dominant and gives it rapid
licks, submitting to the hierarchy.
The low-ranking wolf advances
with submissive posture: ears laid
back and its tail between its legs.
Then it lies down and urinates while
the dominant smells its genitals to
identify it.
MAMMALS 59
Although it looks like the
wolves are playing in this
picture, they are
actually carrying
out a game
involving
power and
hierarchy.
IS THE SIZE OF
THE PACK
DEPENDING ON
THE AVAILABILITY
OF FOOD.
Wolves live in packs made
up of two to three pairs of
adults and their various
generations of offspring.
They cooperate in a
hunting, killing animals ==
several times larger than
themselves. Although 95
they share food, wolves <4
have a hierarchical
order that obliges the
young to make way
for larger and older
family members.
Diversity
DEEP SLEEP NOCTURNAL FLIGHT
RATIONED WATER PLAYING HIDE AND SEEK
RECORD BREATH-HOLDERS THE LANGUAGE OF WATER
AERIAL ACROBATICS LIVELY TUNNELS
NATURAL BUILDERS
DISTINCTIVE STRIPES
Zebras' stripes extend
down to the underbelly. ‘
They confuse predators.
PE eis
wef
here is great variety among them. For example, here you will energy during times when food is scarce. of certain mammals to adapt to the hot
mammals, and in this chapter discover that there are species, such as Here we will also show you how the and dry conditions of the desert. Camels,
we try to show you some bats, that are expert fliers, while others, bodies of some mammals (whales and in particular, are very adept when it
representatives of the most such as dormice, enter into a deep dolphins) are adapted to aquatic life. In comes to retaining and efficiently using
outstanding differences among winter sleep that allows them to save addition, we will also consider the ability liquids.
DIVERSITY
Dormice build their nests out of twigs, moss, and
leaves, although they can also hibernate in
trees, stone walls, or old buildings, creating
a nest from fur, feathers, and leaves. They
then settle into the nest, forming a ball.
When they cannot find a natural refuge,
dormice may settle into birds' nests with
total impunity.
Deep Sleep
ow many times have you heard the expression “dead
as a dormouse”? The comparison is no accident,
although it should be understood that dormice
do not die: they merely hibernate. In the cold season,
low temperatures and scarcity of food lead many
mammals to enter into lethargic states. Body
temperatures drop, heart rates and respiration
slow down, and they lose consciousness. @
J
HOLLOW BALL
ee BALL
‘
Dormice begin to Like‘an ovenbird
form a ball out of nest, the ball
these materials, in must be hollow 4
imitation of the so it can shelter
posture they will the dormouse. FINISHEDIIESEE
RAW MATERIALS adopt during With an entrance in
To build their nests, hibernation. front, the hollow ball
dormice collect has been transformed t
twigs, leaves, moss, into a nest. 7) °
feathers, and hair.
Weight loss after
consuming all
theinreserves
During this period, dormice enter into a de€p.
% ' sleep. Body temperature drops to 342F (1° C),
C appreciably decreasing the,héart rate. In-fact,
HAZEL The energy they consume during hibernation is , up to 50 minutes can transpire between breaths: THEIR BODY
DORMOUSE obtained from the subcutaneous fat layer built up is what they can weigh e », Throughett thesesnonths, they slowly use up J TEMPERATURE
Muscardinus during the autumn. Their nutrition comes from after accumulating fat \ KR \ helt reserves/fosifig up to 50 percent of their DURING
in leaves, bark, nuts, and other (mainly plant) foods. é \) body weightsfheir endocrine system is almost
avellanarius Before the arrival of winter, they stock up on mri Late bese! ves before ) totally, aterest: the thyroid ceases functioning, a | HIBERNATION
SSS dried fruits to increase their energy, allowing Dormicearetver hibernating. does the-interstitial tissue of the testicles.
Habitat Almost all Europe them to easily climb trees and walls. Before fond of oak pets : 4 @ ‘
i aa ss hibernating, they spend all i
Habits Hibernate 4 months their time eating, | \ :
of the year accumulating . — — x | od
- reserves for j ¥
Gestation winter. ‘ 2 r POSITION OF THE BODY
5 } \ 1
Anta ae x 1 = TAIL
3 J ve . — They cover
: {poi ' Sgt BS he ta part of the
< A é < > - body with it.
— ae - m Ff: SSD ‘ } ‘ p ih HEAD
> Weight : > . ‘ a Cae alt rn” ; ’ : Sd, By j ; They hide it
2 ounces ! ( = ) . <4 47 . ‘ A”. OUReT, er ae we A betiind their
H (51g) 35 C — Sat 24 2) Ss : : 4 “ } . | } long tail.
it —— 4 to 7 inches THEIR NORMAL BODY Sa) le aS ae Bi le oe ; S41 a : i J |
1h (10-17 cm) TEMPERATURE. p= % 4 ee B78 Sas ey f : «s ne FEET
4 , remain flexed
Tey @ | j during these
; 8 months / 4 months?) > YL re
3 They are conscious They remain in a s Phew yA — -
rand.active. f state‘of hibernation. 4 > (2) . :) # RESPIRATION ENERGY: HEART
‘ f J “o “/ Fifty. minutes They obtain it from the Heartbeats
val > ; 4 V4 ; C7 P :- a can pass subcutaneous fat reserves decrease
ix Sob a j t v AN) F > : Az between’breaths. they accumulated.in the fall. considerably.
» ny te , at ; ¢ y oe vay
Py * A, a . >
ake ve” : : : : aw a,
1. 4 _ |
J é \
> '
CHESTNUT ! Q \
Its caloric en + §
> contribution Y Ch N ‘
O UTS’. increases rf a at é
ithou h the F : é . j
— )" = Pencil their energy Za v ge ! , BIORHYTHM OF A DORMOUSE WHILE\HIBERNATING
Pe Sallis reserves ——— | 7
" and insects, . : B € e f r f/\' ? j
dormice begin to . ' Sad | ? TEMPERATURE s
feed on nuts prior . ih y . . Pp = ; Tt —-—— yt -
to hibernation. “a : . s . =
D \ wth ,
— q . ‘ ; \
OTHER PLACES FOR HIBERNATION werd oe
O——.— ACORNS f .
The nuts of oak 4 BIRD'S NEST HOLE IN
° trees (genus y “5 If they do not TREE
Quercus) are a 4 se ‘ sm, find a place to ‘an also serve RESPIRATION
favorite food of " s “ig build theirnest, Yas a burrow for
dormice. hey maystake hibernation. IRR ABE BIBI PaO Da AD BRI DR NDP PBRPLED OLD
overga bird'ssnest: Prior Deep Brief Deep After
Feeding Hibernation® Activity |Hibernatiof| Hibernation
64 DIVERSITY MAMMALS 65
Rationed Water The Hump as a Reserve RESISTANCE TO THIRST AND HUNGER
Formed by the accumulation of fat during periods of abundant :
Dromedaries can
amels have developed a sophisticated physiology in order to face life in hot climates. Their nese BUSING. Se CHER IMesc ie alee 2elh SCR a go without food 4
5 re Ei ‘ absence of plant foods. This chemical reaction provides camels with a THE AMOUNT OF WATER and water for
kidneys are capable of greatly distilling their urine to prevent water loss. When sandstorms small but invaluable amount of metabolic water. The breakdown of the DROMEDARIES CAN amt Cie cs g
i i fat produces hydrogen, which combines with inhaled oxygen to CONSUME IN 10 MINUTES sie CY \ ry
worsen, camels curl up on the ground and close their eyes and nasal openings to protect eRe ESTEE OTE Alcala ete Gn 122° F (50° C). HL
themselves. When water and food are scarce, they are able to endure by consuming the reserves iymph, and plasma, they can go without food and water for long BS Sidse he einai
they have accumulated and stored in the hump and internal sacs. ae Tf all the hump's be ec ioe
water is used up,
it hangs off to one
They also have oval-shaped red blood cells, which can easily move hhangs off to
side of the body.
throughout the body even when the blood has become
thickened from dehydration.
HUMP
Fat accumulates and prevents
the excretion of water from
the whole body. This allows
camels to use a minimum of
water.
40% The maximum
percentage of body
/ weight camels can
lose without dying
Camelus : z DE e@
dromedarius ‘ : Speer ins ant
= BODY NOSE
eI Their mucus structure is 100 | f C
Habitat Arabia and Africa iaiabraheie times more complex than that ’ ay l pounds
7 f fh d retains 66 4 Kg
Food Berpivarous their bodies act as coer e ite ars Foire ‘ ’ =.
Average life span 50 years heat retainers, and = : pueag > CAN WELCH THIS UC
= during the night, HAIR
& | = the excess is so thick that it prevents / 2 pounds | 2 quarts
¥ , ™ temperature heat from reaching the skin. . rs
1 eal f ; P
- ' dissipates by When cold is intense, the hair 4 (Ql kg) (2 ))
N n = keeps the camel warm with .
——_ | conduction. its own body heat. ‘ v4 of consumed fat of metabo
i | a : : : water ~
Weight ) : tar . >
; '
ounds y | >
(600 kg) © 4 /.
feet : r :
(3 m) ;
1 &@
idnevs ERYTHROCYTES 240% :
: = > The percentage by which
greatly distill the urine, preventing — f an erythrocyte can swell,
unnecessaty water Hiss lie vane may Normal increasing its ability to
get as thick as syrup and contain : Erythrocyte
double the salt of seawater. In this Swollen Bap sbole Water
way, camels eliminate impurities Erythrocyte
and filter the blood, losing as little
water as possible.
KIDNEYS
concentrate
urine to
retain water.
KNEES ‘
have calluses so
camels can kneel
without getting
burned.
recovers part of
the water. Because
the loop is longer
in dromedaries
than in any other
-" mammal, water
tal ci s fora
_— 7 ' ig time.
- 7
The “ i — s
Se ies. —- r
. of a ae - ~ @
66 DIVERSITY MAMMALS 67
> ars _ “it - : — _—s Se |
=—"E ae eel es — — |
- — z 4
- # ail Z
| Ney & | . . . .
DiGwell a Adaptation in Respiration ae Einan
% ~ a When they dive t t denth hal tivat Upon submerging, it fills The heartirate slows An ample blood flow,
+ at ak a3 © a Be S, wre Wy ~~ stele! wath water, mach foals sh during the al in permlobin,
. . ; an entire physiological mechanism that makes maximum the spermaceti oil an ive, limiting oxygen ransports elevate
perm whal es are unique animals whos € species | Mt S. On the use of their oxygen reserves. This produces what is called a makes it denser. conor levels of oxygen to the
th ili - iv Naximium ) thoracic and pulmonary collapse, causing air to pass from the body and brain.
one hand, they nave tne abiil ! aximum a n
: se a, : ma lungs to the trachea, reducing the absorption of the toxin
' and remain under water without oxygen TO up 0 this by nitrogen. They also rapidly transmit nitrogen from the blood to
ne “lL eans of a complex phy in it -al mechanism that, 0 (elae rate, the lungs at the end of the dive, thus reducing the circulation of
“ = oer re. . ; : lig ; * blood to the muscles. Sperm whales' muscles contain a large
1 use alr in the nu FITIZE mi, or gans amount of myoglobin, a protein that stores oxygen, allowing the
; ab fr : | Ln nly on rm whales to stay underwater much longer.
h . a ot
y a = < ON THE SURFACE WHEN THEY DIVE RETIA MIRABILIA LUNGS
va @) m ] nN utes Blowholetremaine powerful muscles ~~ The retia is a network of absorb
TIME THEY CAN SPEND open, allowing the tightly close the “ sled vessels (miabilia) ahaa
HOUT BREATHING. whales to breathe as opening of the entering the brain. a
— Py 2 mutch oxygen as they blowhole, keeping a
P can before diving. water from entering.
ner Pn oe
~ sill
oxygen into its bod ere. WD eve re
through spiracles located
on the top of its head.
he.
REPRIORISRZAING Oxyceene
Sperm whales can allocate
oxygen to certain vital organs,
\ such as the lungs and heart,
directing it away from the
t digestive system. .
Weight : =
yD 20 to 90 tons
By Comparison $ ,
11 elephants of 8 tons apiece OT Kren — * at ee
MOUT
Because of the placement
Nostril of the nostrils, sperm
wists can swim with their
A mouth open and capture
Muscle etree prey. They feed on squid.
Spenuacelt Organ
Sperm whales' ability to dive to great depths could be due in part to
their spermaceti organ, located in their heads. It consists of a large
mass of waxy oil that helps them both float and take deep dives. Its
density changes with temperature and pressure change. It, like the
melon of a dolphin, directs sound, focusing clicks, since its eyes are of
little use when far from light.
Teeth
They have 18 to 20
conical teeth, weighing up
to 2 pounds (1 kg) apiece,
in each lower mandible.
Mandibular
Bone
COMPOSITION
90% Spermaceti Oil
“. x
prope
ae a dive, the heart —
rate drops (a condition
known as bradycardia), _
which lowers oxygen |
consumption.
Making Use
e 5
r
j A
ee:
¥
of Oxygen
Sperm whales can dive deeper
and stay submerged longer than
any other mammal, because
they have various ways of saving O
oxygen: an ability to store it in @)
their muscles, a metabolism that
can function anaerobically, and AMOUNT OF AIR
the inducement of bradycardia REPLACED IN ONE
during a dive. BREATH
89%
AMOUNT OF AIR
REPLACED IN ONE
BREATH
the whale’
main means of
propulsion.
Dive
True diving champions, sperm whales can dive to
depths of 9,800 feet (3,000 m), descending up to
10 feet (3 m) per second in search of squid. As a
general rule, their dives last about 50 minutes, but they
can remain underwater up to two hours. Before
beginning a deep dive, they lift their caudal fin
completely out of the water. They do not have a dorsal
fin, but they do have a few triangular humps on the
posterior part of their body.
| OFEET (OM)
— \ _ ON THE SURFACE
a They inhale oxygen
through the blowhole
located at the top of
the head.
+ 3,300 FEET
(1,000 M)
90 MINUTES
They store 90 percent
of their oxygen in
their muscles, so they
can be submerged for
a long time.
Di 0 FEET (0 M)
7 \__ ON THE SURFACE
- They exhale all the
air from their lungs;
this is called
spouting, or blowing.
68 DIVERSITY MAMMALS 69
FORCE OF
STARTS UPSIDE
Aerial pect DOWN
The cat begins to fall upside
down and will turn 1802
e
—~ . .. . . . . . . . ..»,-, = i ———_ ll ‘iti re upon its axis (in two stages),
Cr O a 1CS aiid landing upright.
ats have a surprising ability to
land upright. The secret lies in
their skeleton, which is more
flexible and has more bones than that
of any other mammal. Cats' reflexes
allow them to twist using the
physical principle of the conservation
of angular momentum. The principle,
first formulated by Isaac Newton,
FIRST TWIST
In this maneuver, the cat
rotates the front half of its
body 1802 on its body's axis.
The other half rotates only
slightly as a result.
a Strong Slight
Rotation aA
>
Front
states that all bodies in circular elf
movement tend to a constant amount
of energy. Thus, the more the animal =
extends its legs to its axis of wth Messterator® INDEPENDENCE
Like a skater who extends or
rotation, the slower it rotates,
legs in to its axis to The “Brake”
H H A increase the speed of Tt extends its hind : folds the arms to control the
red istri buti ng the total ile as legs perpendicular to speed of rotation, the cat
energy of the system. If the * the axis and reduces moves its hind legs—but
the speed of rotation
of this part. independently of each other.
animal tucks in its legs, it
rotates more rapidly. @
LIKE A SKATER
Name Domestic cat ri | .
1 ue
Family Felidae i 7
Species Felis catus i
{
Adult Weight 4 to 15 pounds (2-7 kg)
Longevity 15 years
Dimensions
’
Itidraws its hind :
legs in to the axis
of the body. i
f
t
f
10 inches
(25 cm) It extends its
front legs at right
-— Axis —
> 5 | ee angles to the axis. To reduce To increase
I i 12 inches i rotation rotation
4inches (30cm) opens arms to closes arms to.
(10 cm) W 4 increase the reduce the radius
radius of rotation. of the rotation.
*e
SECOND TWIST
The cat lowers its hind legs
and completes a full rotation
on its axis. It again carries
Time of the Fall
IF A fall from a short distance usually causes
Le more harm than one from a considerable
Front Half ‘oe : ie . . 4 out two more rotations, one
: , .% } : ;
height, because the cat adopts a defensive The extended legs oa oe . i ; tighter than the other:
posture only when it senses acceleration in the reduce the speed
fall. Upon reaching terminal velocity, it can of rotation of this ;
accelerate no faster, and the cat relaxes, vee It rotates _ ; Sees
stretches out, and offers resistance to the fall. . oa acon
Back Half .¢ AXIS
Now the folded TW i =—s >,
Relaxation legs increase the
O Terminal speed of rotation Front Back
velocity of this part. Half Half
a
. The tail
Defensive stabilizes the
posture weight of the
body during the
descent. FOUR FEET PLACED
UNDER THE BODY
With four feet positioned
under the body, the cat bends
its spine like a parachute and
then merely corrects its
posture for landing.
Equilibrium
IM§ The inner ear in the temporal bone
Leff is divided into the cochlea, the
vestibule, and three semicircular canals.
Inside there is a system of cilia (sense
receptors) and a viscous substance
(endolymph) that generates the |
sense of balance when the two
come in contact with each other.
Tt extends the
hind legs to
the height of
e the front legs.
Cross section of Bulla
a semicircular It holds the
canal cilia, which
are
equilibrium
receptors.
T° ELONGATION
CAPACITY
Extreme Flexibility
Cats do not have a clavicle, and
the articulations of their
vertebrae are more flexible
than those of most mammals.
They can travel five times the
length of their body in one leap.
l/ 8 of a second
TIME IT TAKES TO ROTATE AND
LAND ON ITS FEET 1/2 SECOND LATER
During a rotation,
endolymph moves
the cilia in the
direction opposite
the body's motion.
QUICK AND PRECISE SHAKE
During the rotation, endolymph At the moment LANDING
i ici of landing, the Its front legs make the first
can splash into the semicircular cat slightly contact with the ground.
canals. To return the liquid to its flexes its feet to Then it lands on its hind legs,
place, the cat gives a quick cushion the blow.
shake of its head. and, finally, it relaxes its tail.
70 DIVERSITY MAMMALS 71
Natural Builders
hey have no bricks or cement, but beavers, semiaquatic rodents, )
skillfully manage to build lodges of great architectural of J yy
/ ip J /
Beavers continually repair the dam and add materials
to it. Floating material carried along by the water is
retained in the dam, along with the roots of
vegetation that grows upon it, strengthening the
entire structure.
beauty. They do not work alone, and it is usual for them ,
to act in family groups. Everyone collaborates in building the CNA
home, which is generally located next to a river or lake SAMY SF :
surrounded by forested areas and which can be entered by
only through aquatic tunnels. The task is difficult, and
beavers work their whole lives enlarging, repairing,
and improving their dwelling.
/
[oe i
f
Underwater
ROOF Entrance
Made of trunks, branches,
AMERICAN stones, and mud. In this
BEAVER These are unique structures, of which Galant aes aes dacbicie lr decnemecae a the
f there are several types, which vary by water level, and second, to enlarge
Castor canadensis ue :
area. They are made of interwoven sticks, the flooded areal around the den.
branches, grasses, and moss, and they Dams are built out of sticks and tree
have a central chamber accessible trunks.
Habitat Temperate forests in the from underwater. This chamber has :
United States and Canada its floor above the water line, has of OFFSPRING DRY AREA
Famil Castoridae two entrances, and can measure er ~ ~ . live with their parents. Covered with
y more than 7 feet (2 m) wide ‘ }. ‘ and_are independent SSF tree bark, grass,
Food Herbivorous and 3 feet (1 m) high ( d : after thrée years.* and little pieces
‘ = : <= of wood
Up to 28
inches
(70 cm)
EXIT
—_— Weight Beavers have
66 pounds webbed feet that
(30 kg) they use to dive
12 inches and for other
(30 cm) quick movements.
maintain the structure
of the dam, holding the
Beavers can have positive and . tree trunks in place.
negative effects. They create wetlands CHANGES ‘4 . . : y ; A
for other species and prevent erosion f9 Their introduction into ei? la 4% ‘ y : Ar | . ry ee = rote tia
in some cases. However, their dams ; a ne A f +3 C Y : os \
can also cause floods and create 7 tee co mLChithal
stagnant water, thus : an they become a pest.
destroying other habitats. : -
UNDERWATER
TUNNEL
Mee LEE . Beavers frequently work in groups to gnaw down a trunk
tunnels, generally a and carry it away. One of them cuts the tree with its
remaining underwater pes Be teeth while the others stand guard. This work takes
iaative minutes. . , eae about 15 minutes, and then the tree falls.
= THE
FOUNDATION
Their mandibles
In winter, they store and teeth are
fresh branches in strong, and they
the pond to serve as use their front
a food reserve. feet as hands.
ENTRANCE
Their powerful Here is where BRANCHES
incisors grow they enter; it is The material most used
throughout their lives a straight path in constructing the
at an incline.
lodge. They are used to
make the ceiling and to
keep the inside dry.
but are kept at manageable
length by wear and tear from the
constant work of cutting down trees.
72 DIVERSITY
Nocturnal Flight
ats are the only mammals that can fly. Scientists call them Chiroptera, a term
derived from Greek words meaning “winged hands.” Their forelimbs have been
_/ transformed into hands with very long fingers joined together by a membrane
(called the patagium) that forms the surface of the wing. These mammals’ senses are
so sensitive that they can move and hunt quickly and accurately in the dark. e
Hibernation
These bats spend the winter in a lethargic
state hanging by their feet, faces down, in
caves and other dark places. Bats are warm-
blooded animals while they are active and
become similar to cold-blooded creatures
when they are asleep. They enter into a state
of hibernation more rapidly and easily than
any other mammal, and they can survive in
cold temperatures for many months—even
inside refrigerators—without needing to feed.
Y nour
ie
\ THE SPEED SOME BATS
: ) MAY REACH DURING FLIGHT
HUMERUS RADIUS THUMB
SECOND
(/
FINGER A
wre wy
\ Y
Forests of Ghana and Congo
Famil
FOURTH amily Pteropodae
Length of wingspan 14 inches (36 cm)
xpert Pilo
Moved by their chest and back muscles,
bats' wings push downward and backward,
generating both thrust and lift. Then the
wings spread sideways and upward. Finally
they move forward until the tips almost
rub the bat's head. Many of these flying
mammals can drift through the air, gliding
without flapping and maneuvering by
folding their wings.
Their Radar ‘ ,
Flexible Wings
Most of the time bats fly at night in The animal emits an acoustical The patagium is formed by the
near-total darkness. Instead of light, vibration imperceptible to the membranes between the digits. In
they use a natural system similar to human ear because of its high some species, the wings are also
frequency (about 18 kHz). The
sonar or radar to guide themselves. signal strikes the objects extended by an additional membrane
This system makes use of acoustical around it. (uropatagium), which joins the hind
signals the bats themselves emit while HAND OR WING limbs to the tail. Their wings are not
only used for flying (pushing the air as
if they were oars in water) but also
ELASTIC FIBERS tat
The texture of the wing is help to maintain a constant body
flying. This system allows them to 2] When the signals bounce back, The first finger, or
recognize the location of any object in Lie ety! ulate and is
front of them or of prey, along with its difference—the faster and ) | | } i BE g used as a claw. ;
direction, size, or speed. It is as if they more intense the return signal, Powerful muscles soft and flexible. It is temperature and to trap insects, upon
were seeing without light. the nearer the object or prey. move the entire wing. UROPATAGIUM _ lined with blood vessels. which bats feed.
74 DIVERSITY
Playing Hide and Seek |
ust lik an species of the animal kingdom, some mammals that live in the wild rely on
their bodies' colorations or appearances to disguise their presence. Some mammals imitate
objects in their environment, and others take on the appearances of other fain
stripes, for example, give these animals a very showy appearance—but when mov
natural envifonment, zebras are camouflaged. So in
MAMMALS
In Motion
The patterns of tigers’ coats are
useful in concealing their contours,
_ especially when they are movin
_among the shrubs and bush
lains where they hunt. Elk
jowever, can be concealed
e vegetation they resemble only so
as they keep still.
-
5
na Is. Zebras’ <5
y in their
J
and crypsis, .
(
A
céloration of af makes it difficult
fely onjspeed and sharp senses to distingui
prey from another. Kicking and biting, zebi
defend themselves from attacks by feline predators. The
felines also make use of camouflage strategies to make
attacks one on one. Many ani make use of element
their surroundings or even of other living organi
camouflage themselves. Sloths are anofher exa
of then ammals, they have ng
.. to avoid notices
lage used by animals incapable of defending themsel
1 other way. Aggressive mimicry, on the other hand, 9
Ws organisms to surprise and attack their prey. This Occurs,
for example, with wild felines (mountain lions, 6¢
Which take advantage of their skin colors and
their fur to go unnoticed in their ecosystems, Zebras travelil
herds as a natural form of self-protection. The disruptive
—
en some
much darker
rest of
STRIPES
Ls The coloration of ~
: t their coat changes’
:
with the incidence
and intensity of
sunlight.
i; f
Y,
Different erns
at does not
id colors of
ey are very Skillful at
branches—their small size and short
Inerable when they are on the ground.
surrounding it. Nevertheless, it does have 7?
patterns that allow it, with the help of
N ions, to disguise
n one setting of
ty
itat. In the ite
iform ae
v
aay
.
y ~ PROTECTIVE _ FUR
‘sg 4 2. * “S< SURROUNDINGS _ Shades and differences
= ae *¥ Many have a coat that of color in the coat are
= & ‘
changes color depending similar to tho: e
on the surroundings. tread dry leaves.
7
sy
76 DIVERSITY
MAMMALS 77
aE
.
%. =
The Language of Wate eee (3). Spounds
: po Interpretation «= jin i aay
: é ; , z , ee ae The middl ds th t HUMAN BRAIN RPMI EBATN
he ways in which cetaceans communicate with others of their epee FUN * sounds to the inner eat Gade Dobhinsbertnenences”
H icti i 1 i ay tor ; from 100 Hz up to 150 kHz (the
kind are among the most sophisticated in the animal kingdom. as with other o ean MEF ely un 15
Dolphins, for example, click with their mandibles when in trouble TE a aie = kHz). Low-frequency signals
. . . . . an essential role in rea
and whistle repeatedly when afraid or excited. During courtship and theformation of * ~ Fa ireot conte
mating, they touch and caress. They also communicate through visual papal strata, cetaceans that cannot live alone.
signals—such as leaping—to show that food is close by. They have a wide
variety of ways to transmit important information. — ©
MORE NEURONS
A dolphin's brain,
which processes the
. . signals, has at least
: double the
Common Name Bottlenose dolphin MELON . convolutions of those
Family Delphinidae ; , is an organ filled with low- : 2 of humans, as well as
: density lipids that concentrate
Species Tursiops truncatus Ly to 13 feet (2-4 m)— and direct the pulses emitted,
Adult Weight 330 to 1,400 pounds They reach sending waves forward. The
(150 to 650 kg) —— a 22 noe shape of the melon can be varied >
Longevity 30 to 40 years (35 km/h) to better focus the sounds.
SPIRACLE LIP =
NASAL
e AIR SAC
DORSAL FIN
allows dolphins
to maintain
their equilibrium
in the water.
LARYNX
CAUDAL FIN
has a horizontal
axis (unlike that
of fish), which
serves to propel
dolphins forward.
Emission
Sounds are generated by air
passing through the respiratory
e chambers. But it is in the melon
that resonance is generated and
amplified. Greater frequencies
PECTORAL and intensities are achieved in
FIN this way.
INHALATION
The spiracle opens so
oxygen can enter.
Spiracle
HOW THE pig)
the lungs g ,
SOUND IS
PRODUCED
The nasal air
sacs begin to
inflate.
The nasal
air sacs
deflate
They can go 12
minutes without
taking in oxygen.
cd Air in
the lungs
EXHALATION
Air resonates in
the nasal sacs and
is emitted under
pressure through
the spiracle.
oot
Riese atts
Low-frequency signals are used
for communication with other
dolphins, and high-frequency
signals are used as sonar.
mile per
second
(1.5 km/s)
SOUND WAVES TRAVEL
4.5 TIMES FASTER IN
WATER THAN IN AIR.
Echolocation
The dolphin emits a
series of clicking sounds
from the nasal cavity.
nearly 50 percent
more neurons.
MIDDLE
The melon concentrates These waves bounce
the clicks and projects off objects they SIGNAL
them forward. | encounter in their way. WITH ECHO
Click Click
Echo
00 UL) mee
Part of the signal
bounces back and
returns to the dolphin Os | 6s | 12 | 18s |
in the form of an echo.
The intensity, pitch, and
return time of the echo
indicate the size, position,
and direction of the obstacle.
78 DIVERSITY
Lively ‘Tunnels
abbits are gregarious animals that live in colonies in a series of burrows called warrens.
The burrows are dug underground and are inhabited by females of high social rank.
Rabbits are principally nocturnal and spend most of the day hidden in the burrow, leaving
to eat when night falls. @ 7
RABBIT FOOTPRINTS
Their footprints are
unmistakable, the result of ~ :
their peculiar way of
The area around the burrow
needs two things before the Pits 2
rabbits will at (60 m) walking and jumpin = n
comfortable—grass and teal pe — oe
cover. Generally rabbits GO FROM ITS BURROW.»s dee eae are ;
build warrens in meadows ai : ]
near thickets or rocks. __- \ mi
4 ‘ ‘
’ -
~
. . — 6 inches Py
\ a sae a Se oe “a : (15 cmp
Danger Print es ; Se Piece any = dh du
Warren
t This is the main part of the burrow,
where the adult rabbits tive. Itis
madeiip of a.complex network of
In the presence of
strangers orin other
cases of danger, rabbits
thump the ground
with the back part of
their hind feet,
warningsthe
When they thump;
tabbits produce.a sound
that allthe rabbits%in, the
interconnected.corridors and chambeks.
MOUNDS
others hot to
leave ‘the
burrow:
colony hears Ifta rabbit is
a, trapped, it will ‘emit.a *
sharp squeal that.can be
y heard throughout the
area. ? * FooD
. DEPOSIT
ee ae
_—. a. =, wr 2
> a, dpe SSE
ic “at > -
s “ yore # *" ~ ' «>
; ull i O=—~ PROTECTED INTERIOR Cc) . y
+ “a - Interior tunnels are lined
with vegetation and,
» rabbit fur to keepithem
from deteriorating andito -
- protect thempsfiom ._”
moisture. ~ os
_ " =
on - Rabbits that a Wa.
\ :
= ~S ~ i receive the : : > ty
7; ~ warning will lt “ Po
ae ‘- . remain in place, ~~ % ~ ~ s%
-~ 7 }, § motionless. w& & am 7
~ . ps x tt
~) b ity b es .
- te . ' a . »
a *
_. =e
+ d \
: -_ - « >
s -
OF a
La
Hind Feet
Then it lets its hind
feet land in front of
Front Feet.
Whenit jumps,.it first-lands onjits
frontfeet, which-are bunched
together.
Both feet leave almost, This gives, rabbit
a single footprint; footprints, their
small and not very Peculiart¥-shaped "
distinct, appearance, »-""" %, 3 ee ;
7 ~ " L at r =
‘ “a, W ?
RABBIT FOOTPRINT’ PATTERNS sa = ’
They always follow. this Y’ as igh at 7
| oe ge hp
a z brine 1
—_ rene 4
* —_ —_ *
Walking, Rabbit
Jumping Rabbit
3 New Hop ,
It begins-the cycle
again by-pushing off
with-the’hind-feet:
ary ty
“ ¥. « x \
head ~ w > \ ¥ ;
ere. ri : -
' ,
. -
° ™ a = {
. > |
ye = Secondary corridors -~ * \
pr are often smaller.and not interconnected. :
at They feed ’on herbaceous, and , -
\ The offspring of the younger females live
grassy plants, roots, and bulbs. } there
Some of their excrement is soft, Leak. get ‘
/ covered with mucus, and is re- m" ‘
ingested, the equivalent of : i + i =a, When the mother,leaves \
bovine rumination. } 5, ) her offspring she seals
- f the\ entrance with dirt to
protect them from
ys -
‘
5 to 8 inches"%™,
(12-20 cm) .
FOOD CELLARS \
~ ae
3 to 10 feet -
i ee The*Secondary corridor 7
c = : has only one.exit, which y
——) , is not connected:to the
s warren or other areas.
} — ail
| o
4 =o. ~——
P rr —— ——_ Ca
“ 4. ¥
IS HOW LONG. A BURROW
TUNNEL CAN BE. The young rabbit will
grow in safety there me!
until it is capable of
fending for itself.
=—_ -
qa
o
ss
Pay
Relationship with People
he history of cats goes back 12
million years to the time when
felines began to populate the
Earth. However, their
domestication began 4,000
years ago. The Egyptians decided to
incorporate them into their home life,
thus keeping rats away. Then the
Phoenicians took them to Italy and the
rest of Europe. One of the subjects
Cats are excellent companion
animals and are known for
their great independence and
cleanliness.
discussed in this chapter has to do with
the things that threaten the existence of
many animal species, including the loss
of natural habitats, poaching, pollution,
and illegal pet trafficking. Within the
MYTHS AND LEGENDS
EACH IN ITS PLACE
RAISING HOGS
MILK PRODUCTION
THE HUMAN THREAT
next 30 years, almost one fourth of the
Earth's mammals could disappear.
82 RELATIONSHIP WITH PEOPLE
PEGASUS
Winged horse, son
of Medusa, who
flew to Olympus
and was received
by Zeus.
Thereafter, he
transported
thunderbolts for
the king of the
gods, who placed
his figure in the
night sky.
TROJAN HORSE
Unable to capture the city of Troy during a
siege that lasted 10 years, the Greeks built
a hollow wooden horse, concealed warriors
inside it, and left it on the beach. The
Trojans, thinking it a gift from Poseidon,
brought it into the city. At night, the
warriors left their hiding place and opened
the city's gates to the remainder of the
Greek army, burning and seizing the city.
Myths and Legends
| uman history has always been intimately linked with the various
mammals—after all, people are mammals, too! Numerous myths and
legends have arisen from this relationship, such as that of the wolf
goddess Luperca, who saved Romulus and Remus from death—or the story
of the birth of the Minotaur, in which a queen was caused to fall hopelessly
in love with a bull and give birth to a monster with a bull's head and man's
body. The origin of each myth springs from a particular tradition and means
something different in each culture. @
In Western culture, the
Greeks and Romans have
been the great producers
myths and legends relatin
animals to humans. Huma:
bodies with the heads of bulls
or the limbs of horses are
some of many examples.
MAMMALS 83
MINOTAUR 3 ;
In Greek mythology, this In Eastern culture, animals, especially mammals,
U have played a leading role in myths and legends.
was a creature born Sometimes one animal has various meanings in
with the body of a man various cultures. To Egyptians, cats represent
and the head of a bull harmony and happiness, but the Buddhist world
disapproves of cats because they, along with
snakes, were the only ones who did not cry at
Buddha's death.
that ate human flesh. It
was born on the island
of Crete of a forced
sexual relationship
between Pasiphae, wife
of King Minos, and a
white bull that Poseidon
gave the king to use as
a sacrifice.
UNICORN
This stone seal
depicting a unicorn
is found in the
National Museum of
Jal eA Ad Le }
Pakistan in Karachi ; % a ?
and dates from the { we , =
year 2300 BC. ™% ; ie ‘
LION
The Manjusri Buddha,
seated on the
mythical lion who is
the guardian of
Buddhist doctrine
of
ig
n
CERBERUS
This was the monstrous,
three-headed hound of
Hades, or hellhound,
which guarded the
kingdom of the dead,
preventing the dead
from leaving and the
living from entering.
84 RELATIONSHIP WITH PEOPLE
Each in Its Place |
ature takes care of maintaining its equilibrium, providing each animal its own role
within the food chain. When one of the roles is removed, equilibrium in the region
is lost. In Australia, dingoes were a big problem for sheep farmers, who built a
great fence to protect their flocks. This barrier left the wild dogs without prey and other
species able to move about more freely in search of food. Dingoes are classified as pests
both for farm animals as well as for rabies control.
The Great Fence
sae sd
was designed to keep dingoes out of the southeastern 4 i og
4 part of Australia, protecting flocks of sheep. It ran for a
thousands of miles and was largely successful in its
objective. The number of dingoes in the area declined,
and, although the loss of sheep to predators was
reduced, this decline led to an ecological imbalance }
by increasing the competition for pastureland
among rabbits and kangaroos.
The Introduction of the Dingo/
Tt is thought that dingoes were domesticated animals
> of the Australian Aborigines who lived in the region.
These mammals originated in Asia and were brought to
Australia by humans. They are medium-sized wild dogs with
thick tails and are notable for having a very distinctive howl
instead of a bark. When European pioneers arrived in
Australia, dingoes were accepted, but this rapidly changed
when sheep became an important part of the economy.
CHAIN
Because of the building of the
barrier, herbivorous animals
have more space to graze, safe
from the presence of dingoes.
DINGO
The leading predators
of sheep, dingoes were
isolated from the area.
3,300 miles
(5,320 km)
THE LENGTH OF THE GREAT FENCE.
Dingoes were soon trapped, hunted, and poisoned.
SHEEP
Their population
increased with the
absence of the dingo.
KANGAROO
They found greater
freedom to move about rate |
in search of food. became scarce, making
it difficult for herbivores
such as kangaroos and
sheep to find food.
DINGO. y5 *"-iconnet oot” eae eS.
* Canis dingo» « Aa ~
‘
Its shape changes according
to its upkeep: The Australian
government subsidizes the
undertaking, but sheep
. farmers are the ones who
@ AREA FREE OF DINGOES maintain its
mame ORIGINAL COURSE
CURRENT COURSE
——a
: re
~* . Wool Industry
Australia is second in the world in wool »
borders, constituting’10 percent of world
wool production: In 1989, when part,of the
. famous fence collapsed; about 20,000 sheep
were lost to dingoes. . .
production. It has 110 million'sheep within its
86 RELATIONSHIP WITH PEOPLE MAMMALS 87
e e S I | S
og farming is one of the oldest forms of livestock production.
In fact, the biggest hog producers, the Chinese, began raising
hogs more than 7,000 years ago. But raising hogs has become
more and more complex. Today, to produce large
litters and high-quality pork as quickly as ;
possible, pigs are crossbred.
Older sows coming from
the breeding room and
Once impregnated, they are
taken to the gestation room,
where they will remain for
They give birth to litters of 10
young replacement gilts 114 days, or until two or to 12 animals and can produce
‘ti heratth ill three days before giving over 3 gallons (12 |) of milk
Porl« Prot du ct tio 1) 1 Pe eens ane ea ; daily. Feeding is unrestricted so
PUI FruUUuaee : be naturally or artificially birth. To prevent problems Soe ERO cow ie catIetE The recently weaned ‘
The use of genetics in a pig nursery is complex impregnated. when they GIVE birth, they A Tea Sie piglets enter nursery 2 = é
and important because breeds of pigs are very receive a restricted diet so 9. crates kept at an (— a . —--,)
specific. Here are the most notable differences they do not get fat. ambient temperature
among various breeds. averaging 772 F (25° C). %
sal They are given an initial ‘ pd -
= s tion and remain here eee
MEAT BREEDS MATERNAL BREEDS he Cuts i te
have high weight gain, a They are very prolific, Thesanimallcan be-soldiasa BECON EOIN AND CHOR SS TALL from day 21 to day 45. ; {|
good build, and a high have good maternal skills, 4 d aig hs Ses | me el} ; ; » A
food-conversion efficiency. and produce a large ressed carcass oF In pleces nee Tinea ha This period lasts y
number of piglets. and taken to supermarkets. / approximately 90 .
> Its meat will be used to af = " ‘ days. When the pigs
make sausages or left as Ke ee _— = <> are 150 days old, they
entire cuts.
weigh about 210
Hampshire 7 SHOULDER RIBS HAM beanies ie Sa
= i -%. BLADE
as, Landrace
, by Once they weigh between 210 and
Duroc fi 220 pounds (95-100 kg), the pigs are
transferred to the slaughterhouse.
ro There they are given an electric shock
Yorkshire : “e that renders them unconscious
= before they are killed. They are
Pietrain scalded in hot water to detach
their hair, are bled, and are
CROSS TO OBTAIN A ag FOR CONSUMPTION
100% 100% \
Meat breed Maternal breed
tela a ner
50% Meat breed” 100%
50% Maternal bxeed in sw |
75% Maternal breed
.. Meat beet s Y 4 25% Meat breed
a
FAT
62.5% Meat breed
~ °375% Maternal breed
ae et
FEED es
It is co mmo to use growth hormones to
increase food conversion efficiency and the
lean-meat cohtent in the dressed carcass.
carcass is prepared for final
then eviscerated, and the
\ butchering.
88 RELATIONSHIP WITH PEOPLE
- : !
MAMMALS 89
—— an
— 7
not easy to offer a supply of fresh milk to
popular drink produced industrially.
KEY
1 Milk Status
JAI Raw
“ARI ME Sterilized
Mechanically HE Skimmed
milked milk comes
MC
out at about 992 F ae
(37° C). It is ME Homogenized
immediately cooled mmm Pasteurized
to less than 392 F
(4° C) to prevent
spoilage.
The mi
controlled is ¢
contamination, and it i: D the 1542 F (57-682 C) for
removed from t yt
in large tanker trucl
{
MECHANICAL MILKING
STEEL TEAT CUP
e e
} 10G High-pressure streams of milk | AST T Louis Pasteur
| ensures that the collide with a piston, reducing _ ensures that potentially harmful 1822-95
the size of the fat particles. French chemist. Among
ntil the 18th century, milk was a little-consumed product because
it could be kept for only a few hours without spoiling. It was
Only in the 20th century, after the discovery of pasteurization,
allowing milk to be preserved, did milk become a universally
Skim Milk
’ Pasteurized, Tank
= ANALYSIS REC ION AND Homogenized
COLLECTION e in the plant, i TERILIZATION HEAT Milk Tank
hi osphatase Milk is heated to EXCHANGE
Teat
Vacuum Pump SEALING MACHINE ‘
Milk ‘ is maintained in aseptic
The difference “ z conditions. Processing and
in pressure extracts MAIN DAIRY BREEDS utter and whipped expiration dates are _
the milk. ; ream, the cream is heated to 260° stamped on the container.
BK HOLSTEIN-FRIESIAN F (127° C) to reduce its water —
|
product is uniform in microorganisms are eliminated from the milk i
other things, he
consistency. It consists but does not change the milk's properties. It
= ; 5 : fs r a discovered that the
, of the dispersion of Milk Picton Smaller begins with rapid heating from a source of decomposition of food
: oe the milk's fat globules Pipeline Particles indirect heat, followed by circulation through is caused by bacteria,
= ee by means of friction a cold pipe for quick cooling. and he invented the first
meet urban needs. created under very ae Snir substances
— high pressure. °
= HEATING COOLING
Peroxide solutions are used to
sterilize the containers, and
reagent strips are used to ensure
that no peroxide residue remains.
HOMOGENIZER
Hot Water 1622 F Cold Water 392 F
(72° C) (4° C)
CONTROL ROOM
The various steps of the
processes carried out in
modern plants are automated
ie ; ~ x : ww - a
« 4 ‘ . & “= a and controlled by computers
° rige d = a, ee — P< from a central office.
“if it is between 1352 and
transportation or
processing, eliminating
germs while retaining
the properties of raw
ilk.
From Germany. For
igre han a00 years, content. For yogurt and cheese,
proportions of milk and cream are
these black and 5
white cows have mixed together and appropriate
adapted to bacteria cultures are added.
different climates.
MILK PRODUCTS
7 VO
EESE YOGURT BUTTER
(17th century). They
are notable for their DULCE DE
red spots. ECHE
JERSEY
The most
widespread English
breed. Its angular
frame makes it
ideal for milk
production.
FILLING MA
Except in the
life milk, the machine fills
containers that will allow
the milk to be preserved for
two weeks under
adequately cold conditions.
AYRSHIRE
From southwestern
Scotland. The oldest
of the milk breeds
90 RELATIONSHIP WITH PEOPLE
The Human Threat
ver the next 30 years, almost a quarter of the mammals could disappear from the
face of the Earth, according to the United Nations. The eminent collapse reflects
DEGREE OF THREAT
Extinct
In the Wild
Critically Endangered 500 individuals
Has not been seen for 30 years
Survives in captivity
Families of Primates
Fl Twenty-five percent of the 625
[Lalli species and subspecies of
primates are in danger of extinction.
The principal causes are deforestation,
FAMILY HYLOBATIDAE
Gibbon Siamang
an unequivocally human stamp: hunting, deforestation, pollution, urbanization, Endangered 1,000 to 2,000 individuals midisenimanaieeorruchcaliuniing, FAMILY PONGIDAE
and massive tourism. Experts calculate that more than 1,000 mammals are Vulnerable Up to 5,000 individuals a Cale ar eioe | anetale
the countries of Gabon and Congo,
endangered or vulnerable, and 20 areas of the ey where the majority of chimpanzees
planet have been identified where
probabilities of extinction may
exist in the near future. e@
Affected Regions
@ MAMMALS AT CRITICAL RISK
O UP TO 10 SPECIES ALREADY EXTINCT
@ MORE THAN 10 SPECIES ALREADY EXTINCT
IUCN.
and gorillas live, the population
decreased by more than half between
1983 and 2000.
Chimpanzee
vi
© There are 781 threatened species in the ASIA “Thiol bawoaciaiias tial
Leff region of sub-Saharan Africa, and in South eT | ”
Asia there are 726. South America contains The World Conservation
another 346 endangered species, and Central and — Union was created m
North America have 63 endangered mammals. EUROPE 1948, bringing together
NOMBRE Se a Otter 81 nations and nearly ot
AMERICA Enhydra lutris oO 10,000 specialists.
x @ &
a
Lotaleaperia we aa bid Once a continuous line of sea otter ° ®
More than one out of every five species colonies stretched from the Kuril @ *
of mammals is endangered: 20 to 25 > Islands of Japan to California. Today 2 ° Se s
percent of existing mammalian species. only a few colonies remain in Alaska e
@® and in the lower United States. ®e
1,097 o .¢ P a
Threatened aw ° ; ° ? = e ee oO a
rT Atlantic
species ° ape Dama Gazelle © &
eo | : E 4 2 A on Deer ee
AEG c hie The degradation of their APETEA ° e ° « ° ANTONE
Species . 7 habitat, as well as e Hippopotamus @ S
that are not ®e unregulated hunting, threaten 7 e bad e These are among the
threatened or their existence. In the Sahara, C) i a
for ee there Pacific Ocean e their population fell by 80 e Fou ia ee Shae Aen ane ® 2 o Orangutans
SUTIN ATEE ey percent in only 10 years. Be aly population in Zambia Pongo pygmaeuspygmaeus (Borneo)
162 583 ° es . and the Democratic Tan Pongo pygmaeus abelii (Sumatra)
iti i Ocean a
Critical Vulnerable ° * ce hs as ei ‘ Bag Found in the tropical forests of the islands
Southern - a oe” YR : &% of Borneo and Sumatra. Indiscriminate
SOUTH = : , logging, mining, and forest fires isolat
348 Chinchilla ———@-© auunica fe Right Whale =e e ° ihe Wien fant eeerces We neal
Endangered Chinchilla brevicaudata —« @™® Eubalaena australis Py: e capture of their young, which are then sold
They live in the Andes z A : * as pets.
Mountains of Chile and Peru. ee oe ees ee nee . ~~ ad Hainan Black-crested Gibbon #
Indiscriminate hunting has thei Aa ‘titi ey ab ai A oe d wi es Nomascus nasutus sp. hainanus ® »
decreased the species, and it Me errata oe Ll These primates are among the five bad
is endangered. they are relatively easy to capture. Itis species in most danger of extinction.
ENDANGERED BY COUNTRY estimated that only 3,000 exist today. Only 30 black-crested gibbons are OCEANIA
aa Indonesia has the most endangered known to exist. °
species, followed by the “country of 5 A 1 6 o
120 Fi ki 2 P é
tigers,” India. In Latin America, )
Brazil is first and Mexico second.
100 ' -
Dolphin
80
80 75 i
Cetaceans Giant Panda
I Gray whales, which inhabit the Harbor Porpoise |
60 a arbor Porpois
LLefl_ waters of the northern Pacific and the Ailuropoda melanoleuca
40 39 38 Arctic, are protected. In 1970, sperm whales Sperm Whale EI One thousand bears survive in reserves
32 29 were declared endangered, and today hunting Blue Whale created in China. The disappearance of their
on — them is prohibited. The Indian Ocean has been habitat—caused by the felling of bamboo,
declared a whale sanctuary in an effort to exenee~s. their natural food—as well as the extreme
5 curb hunting, but 7 out of 13 great whales Gray Whale ie difficulty they have reproducing in captivity
in hale
(because of their timidity) are the principal
reasons for the decrease in this species.
remain in danger of extinction, as do a similar
China Cameroon Tanzania Russian Thailand U.S. - &
number of dolphin species.
Federation
Indonesia India Brazil
92 GLOSSARY
Abomasum
Last of the four chambers into which
ruminants’ stomachs are divided. It secretes
strong acids and many digestive enzymes.
Agouti
Rodent mammal of South America measuring
approximately 20 inches (50 cm) and having
large feet, a short tail, and small ears.
Albumin
Protein found in abundance in blood plasma. It
is the principal protein in the blood and is
synthesized in the liver. It is also found in egg
whites and in milk.
Alveolar Gland
Functional production unit in which a single
layer of milk-secreting cells is spherically
grouped, having a central depression called a
lumen.
Biome
Land or water ecosystem with a certain type
of predominant vegetation and fauna.
Biped
Adjective applied to species of mammals that
walk on two feet.
Bradychardia
Lowering of cardiac frequency to below 60
beats per minute in humans.
Bunny
This is a young or growing rabbit.
Carnassial
A typical sharp premolar present in
carnivorous animals that helps them cut and
tear the flesh of their prey more efficiently.
Carpus
Bone structure of the wrist, located between
the bones of the forearm and the metacarpus.
It is made up of two rows of bones.
Chiridium
A muscular limb in tetrapods. It is a long bone
whose anterior end articulates with the
scapular belt. The posterior end articulates
with two bones that connect to the joints of
the digits.
Cloaca
The open chamber into which the ducts of the
urinary and reproductive systems empty.
Cochlea
A structure shaped like a coiled spiral tube,
located in the inner ear of mammals.
Concha
The arched, osseous plate found in each of the
nostrils.
Cones
The photoreceptor cells in the retina of
vertebrates. They are essential for
distinguishing colors.
Convolution
Each of the slight elevations or folds that
mark the surface of the cerebral cortex.
Cortex
The outer tissue of some organs, such as the
brain and kidney.
Counter Shading
The characteristic of protective coloration in
the hair or fur of certain mammals that are
dorsally dark and ventrally lighter.
Cynodonts
Animals that, beginning in the Triassic Period,
start to exhibit characteristics essential to the
lives of warm-blooded animals, making them
relatives of true mammals. They include the
Mammaliaformes.
Dendrite
The branched elongation of a nerve cell by
means of which it receives external stimuli.
Dermis
The inner layer of the skin, located under the
epidermis.
Dichromatic
Refers to mammals, such as mice and dogs,
that have two types of cones in their retinas
and can only distinguish certain colors.
Digitigrade
Refers to animals that use only their digits to
walk. One example is dogs.
Dimorphism
Two anatomical forms in the same species.
Sexual dimorphism is common between males
and females of the same species.
Domestication
The process by which an animal population
adapts to human beings and captivity through
a series of genetic changes that occur over
time, as well as by means of adaptation
processes brought about and repeated over
generations.
Echolocation
The ability to orient and maneuver by emitting
sounds and interpreting their echoes.
Ecosystem
A dynamic system formed by a group of
interrelated living beings and their environment.
Embryo
A living being in the first stages of its
development, from fertilization until it acquires
the characteristic appearance of its species.
Endemism
The characteristic of a specific area where
animal or plant species are natively and
exclusively found.
Endothermy
The ability to regulate metabolism to maintain
a constant body temperature independent of
the ambient temperature.
Epidermis
The outer layer of the skin formed by epithelial
tissue covering the bodies of animals.
Erythrocyte
A spherical blood cell containing hemoglobin,
which gives blood its characteristic red color
and transports oxygen throughout the body. It
is also known as a red blood cell.
Estrus
The period of heat, or greatest sexual
receptivity, of the female.
Ethology
The science that studies animal behavior.
Eumelanin
One of the types of melanin, a darkish brown
color pigment.
Eutheria
One of the infraclasses into which the Theria
subclass is divided, applied to animals that
complete their development in the placenta.
Fetlock Joint
In quadrupeds, the limb joint between the
cannon bone and the pastern.
Follicle
A small organ in the form of a sac located in
the skin or mucous membranes.
Gestation
The state of an embryo inside a woman or
female mammal from conception until birth.
Glomerulus
A ball-shaped structure such as the renal
glomeruli, which are formed by a tiny ball of
capillaries and which filter the blood.
Habitat
The set of geophysical conditions in which an
individual species or a community of animals or
plants lives.
Hibernation
The physiological state that occurs in certain
mammals as an adaptation to extreme winter
conditions, exhibited as a drop in body
temperature and a general decrease in
metabolic function.
Hock
The joint located between the metatarsal and
tarsal bones of the hind limbs of a quadruped.
Homeostasis
The set of self-regulating phenomena that
keeps the composition and properties of an
organism's internal environment constant.
Homeothermy
Thermoregulation characteristic of animals
that maintain a constant internal temperature,
regardless of external conditions. Body
temperature is usually higher than that of the
immediate environment.
Hoof
Horny, or cornified, covering that completely
envelops the distal extremity of horses’ feet.
Iris
The membranous disk of the eye between the
cornea and the lens that can take on different
MAMMALS 93
coloration. In its center is the pupil, which is
dilated and contracted by the muscle fibers of
the iris.
Keratin
A protein rich in sulfur, it constitutes the chief
element of the outermost layers of mammals'
epidermises, including hair, horns, nails, and
hooves. It is the source of their strength and
hardness.
Lactation
The period in mammals’ lives when they feed
solely on maternal milk.
Litter
All the offspring of a mammal born at one
time.
Mammaliaformes
See Cynodonts.
Mammalogy
The science of studying mammals.
Mammary Gland
One of a pair of external secretion organs
characteristic of mammals. It provides milk
to the young during lactation.
Marsupial
Mammals whose females give birth to unviable
infants, which are then incubated in the ventral
pouch, where the mammary glands are
located. They belong to the Metatheria
infraclass.
Marsupium
The pouch, characteristic of female marsupials,
that functions as an incubation chamber. It is
formed by a fold of the skin and is attached to
the outer ventral wall. The mammary glands
are found there, and the offspring complete
the gestation period there.
94 GLOSSARY
Melanin
The black or blackish-brown pigment found in
the protoplasm of certain cells. It gives
coloration to the skin, hair, choroid
membranes, and so on.
Metacarpus
The set of elongated bones that make up the
skeleton of the anterior limbs of certain
animals and of the human hand. They are
articulated to the bones of the carpus, or wrist,
and the phalanges.
Metatheria
The infraclass of the Theria subclass, it
contains species that reproduce partially inside
the mother and then continue their
development inside the marsupium.
Molt
The process by which certain animals shed
their skin or feathers; or, when plants shed
their foliage.
Monotremata
The only order of the Prototheria subclass, it
consists of egg-laying mammals with a
marsupium in which they incubate their eggs.
The mammary glands are tubular and similar
to sweat glands. They are distributed in four
families, half of which are now extinct.
Multituberculate
A group of mammals that lived predominantly
during the Mesozoic Era and that became
extinct during the early part of the Cenozoic
Era.
Neuron
A differentiated cell of the nervous system
capable of transmitting nerve impulses among
other neurons. It is composed of a receptor
site, dendrites, and a transmission (or release)
site—the axon, or neurite.
Nostril
Each of the openings of the nasal cavities that
lead to the outside of the body.
Omasum
A ruminant's third stomach chamber. It is a
small organ with a high absorptive capacity. It
permits the recycling of water and minerals
such as sodium and phosphorus, which may
return to the rumen through the saliva.
Oviduct
The duct through which the ova leave the
ovary to be fertilized.
Oviparous
Refers to animals that lay eggs outside the
mother's body, where they complete their
development before hatching.
Papilla
Each of the small, conical elevations on skin or
mucous membranes, especially those on the
tongue, by means of which the sense of taste
functions.
Pasteur, Louis
(1822-95) The French chemist who developed
pasteurization and other scientific advances.
Pasteurization
The process that ensures the destruction of
pathogenic bacteria and the reduction of
benign flora in milk without significantly
affecting its physicochemical properties.
Patagium
The very fine membrane that joins the fingers
and anterior limbs with the body, feet, and tail
of bats.
Pheomelanin
One of the types of melanin, a yellowish-red
pigment.
Pheromone
A volatile chemical substance produced by the
sexual glands and used to attract an individual
for reproductive purposes.
Phylogeny
The origin and evolutionary development of
species and, generally, genealogies of living
beings.
Placenta
The spongy tissue that completely surrounds
the embryo and whose function is to allow the
exchange of substances through the blood. It
also protects the fetus from infections and
controls physiological processes during
gestation and birth.
Placentalia
The name by which the species in the Eutheria
infraclass orders are also known.
Plantigrade
Refers to mammals that use the entire foot in
walking. Humans are plantigrade.
Polyandry
Refers to the relationship in which a female
copulates with various males during one
breeding period.
Polyestrous
Refers to an animal that has multiple annual
breeding, or reproductive, periods.
Polygyny
The social system of certain animals, in which
the male gathers a harem of females.
Prototheria
A subclass of the mammal class, it has a single
order, Monotremata.
Quadruped
Refers to a four-legged animal.
Rabbit Warren
A burrow that rabbits make to protect
themselves and their offspring.
Reticulum
The second chamber of a ruminant's stomach.
It is a crossroad where the particles that enter
and leave the rumen are separated. Only small
particles of less than a 12th of an inch (2 mm)
or dense ones greater than 1 ounce per inch
(1.2 g per mm) can go on to the third chamber.
Retina
The inner membrane of the eyes of mammals
and other animals, where light sensations are
transformed into nerve impulses.
Rod
Along with cones, rods form the photoreceptor
cells of the retina of vertebrates. They are
responsible for peripheral and night vision,
though they perceive colors poorly.
Rumen
The first chamber of a ruminant's stomach. It
is a large fermentation vessel that can hold up
to 220-265 pounds (100-120 kg) of matter in
the process of being digested. Fiber particles
remain there between 20 and 48 hours.
Ruminate
The process of chewing food a second time,
returning food to the mouth that was already
in the chamber that certain animals
(ruminants) have.
Scapula
Triangular bone, also called the shoulder blade.
With the clavicle, it forms the scapular belt.
Scavenger
Animals that eat organic forms of life that
have died. They help maintain the equilibrium
of the ecosystem by feeding upon dead
animals, breaking them down.
Spermaceti
A waxy substance contained in the organ that
bears the same name, located in the head of
the sperm whale. It is believed that it aids
deep dives, although some specialists believe
that it may assist echolocation.
Spinal Cord
An extension of the central nervous system.
Often protected by vertebrae, this soft, fatty
material is the major nerve pathway that
carries information to and from the brain and
muscles.
Synapsids
These are also known as therapsids and are
described as mammal-like reptiles. They are a
class of amniotes that were characterized by a
single opening in the cranium (fenestra) behind
each eye in the temple. They lived 320 million
years ago, during the late Carboniferous
Period. It is believed that modern mammals
evolved from them.
Tapetum Lucidum
A layer of cells located behind the retina of
some vertebrates that reflects light toward
the retina, increasing the intensity of the light
it receives. It heightens the perception of light
in near-darkness.
Trichromatic
Refers to mammals whose eyes have three
classes of cones—sensitive to red, green, or
blue.
MAMMALS 95
Trophic Chain
System formed by a group of living beings that
successively feed on each other.
Udder
Saclike organ containing the mammary glands
of certain female mammals.
Ungulate
A mammal that supports itself and walks on
the tips of its digits, which are covered by a
hoof.
Uropatagium
The membrane that bats have between their
feet. It also encloses the tail.
Viviparous
Refers to animals in which the embryonic
development of offspring occurs inside the
mother's body and the offspring emerge as
viable young at birth.
Vomeronasal Organ
An auxiliary organ of the sense of smell
located in the vomer bone between the nose
and the mouth. Sensory neurons detect
different chemical compounds, usually
consisting of large molecules.
Warren
A burrow where certain animals raise their
young.
Weaning
The process by which a mammal ceases to
receive maternal milk as its subsistence.
Whiskers
Very sensitive hairs of many mammals. They
are often located near the mouth, like a
mustache.
96 INDEX
MAMMALS 97
Index
A
acoustical guidance system
bats, 72
See also echolocation
Africa, endangered species, 90-91
aggressive mimicry, 74, 75
American beaver, 70-71
antler, 36-37
Arabian camel (dromedary camel), 64-65
Arctic fox, 30
artificial insemination, 86-87
Asia, endangered species, 91
Australia, 10-11, 84-85, 91
Ayrshire (breed of cattle), 88
B
bacteria, ruminants, 53
Bastet, 83
bat, 23, 31, 60, 72-73
bear
brown, 15
grizzly, 15
polar, 6-7, 16-17, 31
beaver, 12, 70-71
bellow, 37
See a/so communication
Bengal tiger, 18-19
binocular vision, 14, 26, 51, 57
biomass, 54
birth, 44
blood, 67
blowhole, 67
blue whale, 5
body temperature, 14, 16-17
balling up, 62-63
camel, 64
dormice, 62
fur, 8
hibernation, 15, 62
See also homeothermy
bonding phenomenon, 45
bone: See skeleton
Borneo, 91
bottlenose dolphin, 14, 76-77
bradycardia, 67
brain, 15, 77
breathing, 66-67
breeding, 86
brown bear (grizzly bear), 15
buffalo, 55
burrow, rabbits, 78-79
C
call, 72
See also communication
camel, 15, 61, 64-65
camouflage, 30, 74-75
carnivore, 50-51, 54
cat (feline)
balance, 68-69
camouflage, 74-75
cheetahs, 24-25, 55
companion to humans, 80-81
domestic, 68-69
equilibrium, 69
flexibility, 69
Geoffroy's cat, 55
history, 80
lions, 50-51, 55
mythological, 83
paws, 23
skeleton, 68
small-spotted genet, 54
tigers, 19, 26-27, 74-75
vision, 26-27
caudal fin, 76
Cerberus, 82
cetacean (aquatic mammal), 15, 23, 66-67, 76-
77,90-91
See also dolphin; sea lion; seal; whale
cheetah, 24-25, 55
chimpanzee, 22-23, 48-49, 91
chinchilla, 30, 90
chipmunk, 14, 75
Chiroptera (bat), 23, 72-73
circulatory system, 14
claw, 23, 25
coati, 31
cochlea, 28, 69
coloration, 74-75
colostrum, 44
communication
bats, 72
chimpanzees, 48, 49
deer, 37
dolphins, 76-77
meerkats, 57
playing, 48-49
rabbits, 78
underwater, 76-77
wolves, 58
companion animal, 80-81
consumer, trophic pyramid, 54
continent, 11
corpuscle, 31
cottontail rabbit, 34
cow, 46-47, 52-53, 88
cranium (head), 15
Cretaceous Period, 8, 12
D
dairy farm, 88-89
dam, 70-71
Dama gazelle, 90
deer, 36, 52-53
defense mechanism, 74-75
dentition: See teeth
dermis, 30-31
digestion, 52-53
digitigrade (foot), 22
dingo, 84-85
diving, whales, 67
dog
developmental stages, 44-45
dingoes, 84-85
field of vision, 27
greyhound, 24
mythological, 82
nose, 29
paw, 22
sense of hearing, 28
sense of smell, 28-29
sense of taste, 29
dolphin, 14, 76-77
domestic cat, 68-69
dormouse, 60-61, 62-63
dorsal fin, 76
dromedary camel (Arabian camel), 64-65
E
eagle, 57
ear
anatomy, 8, 28
bones, 15
cats, 69
cochlea, 69
dogs, 28
eastern cottontail rabbit, 34
eating
giraffes, 32-33
ruminants, 52
echidna, 10, 35, 38-39
echolocation, dolphins, 77
ecology, 54-55
ecosystem, 54-55
egg, 32, 35, 38
elephant seal, 13, 15
endangered species, 5, 90-91
endolymph, 69
energy, trophic pyramid, 54
epidermis (skin), 30-31
equilibrium, 69, 84-85
erythrocyte (red blood cell), 64
Europe, endangered species, 90
Eutheria: See placental mammal
evolution, 74
extinction, 90-91
causes, 81
polar bears, 7
See also endangered species
extremity, 22-23
fins, 23
opposable thumbs, 49
wings, 23
eye, 26-27
F
falling, feline equilibrium, 68-69
family, 59
farming, 86
fat reserve, 17
fat storage, 62-63, 65
fatty tissue, 30
feline: See cat
ferret, 55
fin, 23, 76
finger, 49
flexibility, 68-69
flight, 24-25, 72-73
flying squirrel, 24-25
food
dormice, 62
lions, 51
pork, 86-87
food chain, 54-55, 84-85
foot, 9, 20
fossil, 11
fox, 30
fruit bat, 73
fur, 30-31
body temperature, 14
camel, 64
camouflage, 30, 74-75
functions, 19, 30, 75
hair types, 31
mimicry, 75
polar bear, 15, 16, 17
G
game
chimpanzees, 48
wolves, 59
gazelle, 55, 90
genet, 54
genetics, 86
Geoffroy's cat, 55
gestation, 11, 35, 42
giant panda, 91
gibbon, 91
giraffe, 13, 32-33, 74
gland
milk-producing, 46-47
sebaceous, 31
sweat, 14, 30
goat, 22
Gondwana (continent), 11
gorilla, 14-15, 91
gray whale, 90-91
greyhound, 24
grizzly bear (brown bear), 15
growth hormone, 87
H
habitat, 15, 90-91
Hainan black-crested gibbon, 91
hair
body temperature, 14
camel, 64
camouflage, 30
functions, 19, 30, 75
98 INDEX
MAMMALS 99
mimicry, 75
polar bear, 15, 16, 17
types, 31
hand, 9
hare, 27, 30
hazel dormouse, 62
hearing, 28
See also ear
herbivore, 52-53, 54
hibernation
bats, 73
body temperature, 5, 15
dormice, 62
polar bear, 17
weight loss, 63
hierarchy, social, 58-59
hippopotamus, 91
hog (pig), 86-87
Holstein (breed of cattle), 88
homeostasis, 16
homeothermy (body temperature)
balling up, 62-63
dormice, 62
hibernation, 5, 15
polar bears, 16-17
See also body temperature
hominid, 15
homogenization, 89
hoof, 20, 22
horn, 36-37
horse, 20-21, 22, 24, 82, 83
human
adaptation, 15
animal relationships, 80-91
brain, 77
classification, 15
destructiveness, 5
feet, 22-23
field of vision, 27
survival, 4-5, 15
hunting
cheetahs, 24
lions, 50-51
tigers, 26
wolves, 59
hyena, 55
I
Indonesia, 91
insulation, 31
IUCN (World Conservation Union), 91
J
jackal, 56
jaw, 15
Jersey (breed of cattle), 88
Jurassic Period, 8, 12
K
kangaroo, 40-41, 84-85
kidney, 64
koala bear, 35
L
lactation
cows, 46-47
distinguishing feature, 46
kangaroo, 40
marsupials, 40
placental mammals, 44
platypus, 39
rabbits, 34
weaning, 34
language
monkeys, 49
underwater, 76-77
See also communication
legend, 82-83
life cycle, 34-35, 40
life span, 34
ligament, 20
limb
fins, 23
functions, 15, 22
wings, 23
lion, 50-51, 55, 83
livestock
cows, 88
hogs, 86-87
sheep, 84-85
locomotion, 22, 79
longevity, 35
loop of Henle, 64
Luperca, 82-83
M
macaque monkey, 30
mammal
aquatic: See cetacean
Australian, 84-85
beginnings, 4-5, 7, 8
body temperature: See body temperature;
homeothermy
bone structure, 8-9
camouflage, 30, 74-75
carnivores, 50-51, 54
circulatory system, 14
classifying, 22
coloration, 74-75
common characteristics, 14-15, 16-17, 46-47
communication: See communication
dentition: See teeth
diversity, 5, 60-79
education, 48-49
endangered, 5, 90-91
extinction, 7, 81, 90-91
extremities, 22
family, 59
fastest, 24
features, 8-9
feeding, 34: See also lactation
flying, 24-25, 72-73
food chain, 54-55, 84
foot, 9
fur: See fur
habitat, 15
hair: See hair
hand, 9
herbivores, 52-53, 54
hierarchy, 58-59
humans: See human
insulation, 31
lactation: See lactation
life cycle, 34
life span, 34, 35
marsupials: See marsupial
mimicry, 74-75
monotremes: See monotreme
movement, 20-21, 22, 79
mythological, 82-83
nocturnal, 72-73
number of species, 5, 14, 90
omnivores, 13, 55
origins, 4-5, 7, 8
placental: See placental mammal
playing, 48-49, 59, 76
posture, 9
prominence, 12
reproduction: See reproductive cycle;
sexual reproduction
running, 20, 24-25, 51
sense of smell, 28-29
senses, 19, 28-29
skeletal structure, 20-21
skin, 30-31
slowest, 74
social groups, 56-57, 58-59
socializing, 48-49
species, 5, 14, 91
subclasses, 10
tail, 9, 21, 25, 51
types, 9
ungulates, 20
vertebrate, 21
vision, 14, 18
water conservation, 64-65
Mammaliaformes, 8
mammary gland, 15, 46-47
mandrill, 13
marsupial, 9, 10
defining characteristics, 11
gestation, 35
kangaroo, 40, 84-85
koala bear, 35
opossum, 11
pouch, 40-41
Tasmanian devil, 11
wallaby, 35
marsupium, 40-41
mating, 36-37
meerkat, 56-57
melon, dolphins, 76, 77
Merkil's disk, 31
metabolism, 17, 25
Metatheria: See marsupial
migration, polar bears, 17
milk, 15, 34, 40, 46-47, 88-89
See also lactation
milk production, 88-89
mimicry, 30, 74
Minotaur, 82, 83
monkey
chimpanzee, 22-23, 48-49
endangered, 91
gibbon, 91
hanging, 49
macaque, 30
mandrill, 13
monocular vision, 14
monotreme, 9, 10, 32, 35, 38-39
morganucodon, 8-9
mouth, 15
movement, 22
multituberculate, 9
muscle, 20
myoglobin (protein), 67
myth, 82-83
N
nest, 63, 78-79
Newton, Isaac, 68
night vision, 18, 26-27
North America, endangered species, 90
nose
camel, 64
dog, 28-29
O
Oceania, 10-11
offspring, 34-35
omnivore, 13, 55
opossum, 11
opposable thumb, 49
orangutan, 91
organ, 64
otter, 90
oxygen, 66, 67
P
pack, 58-59
panda bear, 91
pant-hoot, 48
Pasteur, Louis, 89
pasteurization, 88-89
pastureland, 84-85
patagium, bats, 73
100 INDEX
MAMMALS 101
paw, 23, 25
pectoral fin, 76
Pegasus, 82
pet, 80-81
photosynthesis, 54
physiology, 15
pig (hog), 86-87
placenta, 42, 43
placental mammal, 9, 10, 11
branches, 12
defining characteristics, 12-13, 42-43
development, 42-43
lactation, 44
life cycle, 34
plantigrade (foot), 22
platypus, 10, 35, 38-39
playing, 48-49, 59, 76
polar bear, 6-7, 16-17, 31
porcupine, 31
pork, 86-87
pouch, 40-41
predator, 54
prehensile digit, 22
primate
characteristics, 15
chimpanzee, 22-23, 48-49
endangered, 91
feet, 22-23
gibbon, 91
gorilla, 14-15
hanging, 49
hominid, 15
human: See human
mandrill, 13
producer, trophic pyramid, 54
protective mimicry, 74
protein, 67
Prototheria: See monotreme
pulmonary collapse, 67
pupil, 26
puppy, 44-45
Q
quill, 31
R
rabbit, 34, 78-79, 85
raccoon, 12
rat, 42-43
red deer, 36-37
red kangaroo, 40
regurgitation
ruminants, 52
weaning, 45
reproductive cycle
echidnas, 35, 38-39
kangaroo, 40
koala, 35
length, 35
marsupial, 40
monotremes, 35, 38-39
placental mammals, 12, 42-43
platypus, 38-39
rabbit, 34
rat, 42-43
reptile, 8
respiration
cheetah, 24
underwater, 66-67
retina, 27
rodent
beaver, 70-71
chipmunk, 14
dormice, 60-61, 62-63
flying squirrel, 24-25
gestation, 42-43
multituberculates, 9
rat, 42-43
semi-aquatic, 70-71
squirrel, 24-25
ruminant, 52-53
rumination, 52-53
running, 20, 24-25, 51
S
scavenger, 55
sea lion, 31
sea otter, 90
seal, 13, 15
sexual reproduction, 32
echidna, 38-39
marsupial, 35
mating, 36-37
monotremes, 38-39
pigs, 86-87
platypus, 38-39
red deer, 36
sheep, 52-53, 84
shelter
beaver dam, 70-71
rabbit burrow, 78-79
short-beaked echidna, 35
shrew, 5
siamang, 91
Siberian flying squirrel, 24-25
sight: See vision
sign language, chimpanzees, 49
skeleton
cats, 68
horses, 20-21
skin, 15, 30-31
slaughterhouse, 87
sloth, 25, 74
small-spotted genet, 54
smell, sense of, 28-29
social structure
meerkats, 56
wolves, 58-59
socialization, chimpanzees, 48-49
sound wave, 77
South America, endangered species, 90
southern right whale, 90-91
species
endangered, 5, 90-91
number, 5, 14, 91
sperm whale, 66-67, 90
spermaceti organ, sperm whales, 66
spiracle, 66, 76
squirrel, 24-25
stereoscopic vision, 18
sternum, 20
stomach, ruminants, 52-53
Sumatra, 91
sweat gland, 14, 30
T
tail
cheetah, 25
lion, 51
rodent, 9
structure, 21
Tasmania, 11
Tasmanian devil, 11
taste, 29
teat, 46
teeth
beavers, 70, 71
carnivores, 50
growth, 14
herbivores, 52
horses, 20
Mammaliaformes, 8
types, 14
whales, 66
temporal bone, 69
tendon, 20
territory, 57
Tertiary Period, 8
Theria (mammal subclass), 10
thoracic collapse, 67
three-toed sloth, 25
thumb, 49
tiger
Bengal, 18-19
camouflage, 74-75
vision, 26-27
titi monkey, 91
tongue, 29
tool, chimpanzees, 49
tooth: See teeth
Triassic Period, 8
Trojan horse, 82
trophic pyramid, 54-55
tunnel, 78-79
U
udder, 46
ungulate, 20, 22
unicorn, 83
uropatagium, 73
UV radiation, 30
Vv
vertebra, 21
vision
binocular, 14, 26, 51, 57
lions, 50-51
monocular, 14
night, 18, 26-27
stereoscopic, 18
tigers, 26-27
W
Wales, 4
wallaby, 35
warren, rabbits, 78
water conservation, camels, 64-65
weaning, 45
whale
blue, 5
fins, 23
gray, 90-91
life span, 34
southern right, 90-91
sperm, 66-67, 90
wing, 23, 72-73
wolf, 30, 55, 58-59, 82-83
wool, 31, 85
World Conservation Union (IUCN), 91
Z
zebra, 51, 55, 60-61, 74
oe
MAMMALS
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HUMAN BODY I
Britannica Illustrated Science Library
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Contents
What Are We
Made Of?
Page 6
Bones and
Muscles
Page 18
: Internal Systems
and Organs
Page 34
a
FS? —
AE Pi — “an
hz The Senses
i ds h
ZA and Speec
Page 68
Si
=~) a
— Control
A
Centers
Page 80
i ewiRiy. WN
A LIVING STRUCTURE
The skeleton consists of
206 separate bones,
which differ in form, size,
and name. It supports
and shapes the body,
protects the internal
organs, and—in the
bone marrow of certain
bones—manufactures
various types of blood cells.
A Perfect
Machine
ow can we understand what we are?
What are we made of? Are we aware
that all that we do—including reading
this book—is the work of a marvelous
machine? We know very little about how we
are able to be conscious of our own actions;
nevertheless, even though we are usually not
very aware of