Penguins are flightless marine birds that dwell
only in the southern hemisphere. They do not
inhabit the Arctic, where polar bears live. There
are seventeen generally recognized species of
penguins. Six species, the Adelie, gentoo, chinstrap,
rockhopper, king, and emperor penguins,
live in the cold environments of the Antarctic region.
The rest live in subantarctic and temperate
regions. The macaroni, fiordland, Snares, erectcrested,
yellow-eyed, fairy, and royal penguins
live off the coasts of New Zealand and Australia
and nearby islands. The Magellanic and Humboldt
penguins live off the coast of South America.
The African penguin lives off the southern coast of
Africa, and the GalГЎpagos penguin is native to the
GalГЎpagos Islands. Penguins spend much of their
lives in the ocean, coming to shore mainly to
breed.
Physical Characteristics
All penguins are black with white undersides,
and are commonly described as wearing tuxedos.
This color pattern acts as camouflage when the
penguin is swimming, protecting it from predators.
From underneath, the white belly blends
with the bright water surface, and fromabove, the
black back is indistinguishable from the dark
water. Penguin species can be grouped according
to common characteristics. Banded penguins have
black and white stripe patterns on their chests and
heads. The crested penguins all have bright yellow
or orange plumes on their heads. Brushtail
penguins have long stiff tail feathers. The king
and emperor penguins have bright yellow and orange
chest and head patches, and the yellow-eyed
penguin has a yellow crown. The fairy penguin's
feathers are bluish.
The emperor penguin is the largest, at nearly
four feet tall and seventy-five pounds. The small
fairy penguin is sixteen inches tall and about three
pounds. All have solid, heavy bones that help
them dive deeply into the water. They have
streamlined bodies that move smoothly through
the water as they pump their strong, flipperlike
wings and steer using their webbed feet and tails
as rudders. Penguins can hold their breath for
many minutes at a time, and they frequently leap
out of the water, porpoiselike, to take inmore air.
On land, penguins walk with an awkward
sideways waddle. Because their short legs are set
back on their bodies, they stand erect and must
hold out their flippers for balance. Penguins often
toboggan themselves by flopping on their bellies
and pushing with their flippers and feet.
Penguin feathers are tiny and stiff, overlapping
to form a waterproof coat. An underneath layer of
down helps to trap warm air and protect the penguin
from the cold water and wind. Penguins of
the Antarctic region have an insulating layer of
blubber. Those in temperate climates often have to
cool themselves down by ruffling their feathers
and holding out their flippers. They can control
the flow of blood to their unfeathered areas, such
as the feet and under their flippers, which helps
regulate their body temperature. Penguins preen
their feathers regularly, to spread waterproofing
oil from a gland near the tail.
Feeding Behavior and Enemies
Penguins are carnivores. They eat many types of
small sea creatures, such as fish, squid, and krill.
After locating a school they snatch quickly with
their sharp beaks. The tongue and upper palate
are covered with stiff spines that grip the slippery
food and assist in moving it toward the throat.
Penguins make several catches per dive, swallowing
the prey whole along with some seawater.
Their specialized salt glands above each eye help
them drain the extra salt they ingest.
Penguins usually enter and exit the water in
large groups, to protect themselves from predators
who often lurk near the shore. Their main enemies
are sea lions, leopard seals, and killer
whales. On land, adult penguins are safe. Petrels,
skuas, gulls, and sheathbills hunt babies and eggs.
Reproduction
Most penguins follow an annual breeding cycle
that begins in the spring, but timing varies according
to species and climatic conditions. The GalГЎpagos
penguin will breed any month that the
water temperature is right, and sometimes twice
a year. Emperors begin their cycle in autumn,
so there is a good food supply
when their chicks hatch in spring.
King penguins only reproduce
twice every three years, because
they follow a fifteen-month cycle.
Some penguins nest on the
shore and others travel many miles
inland to reach their rookeries, and
they return to the same ones each
year. Penguins are social, and one
rookery may have thousands of
penguins in closely spaced nests.
They often squabble over nesting
materials, mates, and territory.
Nests are built of grass or stones on
the ground, in rock crevices, or in
burrows. The male engages in an
ecstatic display to attract a female,
pointing his beak, flapping his flippers,
and squawking. Penguins
usually mate for life, and in subsequent
years the pair will greet each
other affectionately. Two eggs are
laid, and the parents take turns incubating
for a few weeks at a time
while the other leaves to feed. The
incubating parent does not eat,
and often loses a great deal of
weight. Each penguin has a brood
patch, an area of bare skin on its
lower belly, that allows for better heat transfer to
the eggs. Incubation varies fromfive weeks for the
small fairy penguin to nine weeks for the emperor.
The king and emperor penguins are exceptions
to the nesting rule. They lay only one egg, which
they cradle on their feet instead of building a nest.
They cover it with a flap of skin to keep it warm.
Kings take turns incubating, while with emperors,
only the male incubates.
Chicks are born down-covered, except for emperor
chicks, which are naked. The parents brood
them while they are young and feed them regurgitated
food. When the chicks get too large for
brooding, they huddle in crГЁches while the parents
leave to hunt for food. When the chicks are
grown and go off on their own, the parents molt.
They cannot go into the water without their full
coats of feathers, so they fast during this two- to
four-week period.
Classification:
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Aves
Order: Sphenisciformes (penguins)
Family: Spheniscidae
Genus and species: Six genera and twenty-five species, including
Eudyptes chrysocome (rockhopper penguin), E. pachyrhychus
(fiordland penguin), E. robustus (Snares penguin), E. sclateri
(erect-crested penguin), E. chrysolophus (macaroni penguin), E.
schlegeli (royal penguin); Spheniscus magellanicus (Magellanic
penguin), S. humboldti (Humboldt penguin), S. mendiculus
(GalГЎpagos penguin), S. demersus (African penguin); Pygoscelis
adeliae (Adelie penguin), P. antarctica (chinstrap penguin), P. papua
(gentoo penguin); Aptenodytes patagonicus (king penguin),
A. forsteri (emperor penguin); Megadyptes antipodes (yelloweyed
penguin); Eudyptula minor (fairy penguin)
Geographical location: Along the coasts of Antarctica, Australia,
New Zealand, South Africa, Chile, Peru, Argentina, and the
GalГЎpagos Islands
Habitat: Oceans and coasts in both cold and temperate latitudes
Gestational period: Incubation varies by species fromthirty-three
to sixty-four days
Life span: Twenty to thirty years
Special anatomy: Aerodynamic body shape; flippers; webbed
feet; short, stiff, overlapped feathers; spiked tongue
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