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The only penguin that has to cope with
extreme cold is the Emperor penguin. The shape of their body helps them to
survive. They have short wings that help them to dive up to 900 feet to
catch larger fish. They can swim 10-15 kilometers an hour which lets them
escape their main enemy, the leopard seal. They can stay warm because they
have a thick layer of down under the outer feathers and a layer of blubber.
The layer of downy feathers trap air that keeps the body heat in and cold
air and water out. They also have large amounts of body oil that aids in
keeping them dry in the water. Like all penguins, the Emperor has a
thick layer of insulating feathers which are designed to keep them warm in
water, remembering that heat loss in water is much greater than in air. In
addition to this, the Emperor has the largest body mass of all penguins,
which further reduces relative surface area and heat loss. |
| They also are able to control blood flow
to their extremities, reducing the amount of blood which gets cold, but
still keeping the extremities from freezing. In the intense antarctic winter, the male Emperor penguins (the females are at
sea) huddle together to keep warm and rotate position to make sure everyone
gets a turn at being on the cold edge.Getting cold is not really a problem for
most penguin species, most have trouble staying cool when out of the water.
Penguins often hold their flippers out to radiate heat and make their
feathers stand up to flush out some of the warm air trapped within. Some
species have bare patches of skin on the face with which to radiate heat,
while others nest underground or in forest. The diet of penguins varies
between species and in some cases, location. The species taken include a
wide range of fish, squid, octopus and euphausids (shrimp-like animals).
Some species of penguin target surface-schooling fish species while others
are mid-water or bottom feeders. The size of penguin chicks at hatching
varies according to the species. Blue penguins have the smallest chicks and
weigh just 35 grams at hatching. When penguins hatch, they are initially
covered in a sparse down, usually brown with a white chest. After a week or
two this is replaced with a much thicker layer of secondary down. When the
chick approaches full size the down is replaced by feathers. |
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