Many people believe -- mistakenly -- that penguins are mammals. They are, in fact, birds with special adaptations: Their wings have developed in to flippers, which they use to propel themselves in the water. They have very dense coats of feathers, the densest of any bird species, for protection against the cold and the water. They use their feet as rudders to steer themselves in the water. And their bodies are aerodynamically shaped so they can glide effortlessly through the water (figure A).
There are 17 known species of penguins, which range in height from 8" up to 4'. The largest, the emperor penguin (figure B), can weigh as much as 90 pounds; the second-largest, the king penguin (figure C), stands about 40" tall and weighs up to 45 pounds. Some species, such as the rockhopper (figure D), are referred to as crested because of the tufts of feathers growing on their heads (the rockhopper gets its name from the fact that it bounces across rocks with its feet together). The gentoo penguin (figure E) looks as if it's wearing earmuffs, and the chinstrap's (figure F) name is self-explanatory!
Penguins have webbed feet and very sharp claws, which they use for climbing on rocks and ice. A "preen gland" is located at the base of each penguin's tail; the bird manipulates this gland to stimulate the production of oil, which is then distributed through the feathers to waterproof and insulate them. The black-and-white coloration, or countershading, helps them blend in with their surroundings: the black feathers on the upper part of their bodies help them hide from predators that may be above them, while the white underside of their bodies camouflages them from below.
Ask the Expert
Q: How can I break my cat's habit of scratching my furniture?
A: Cats by nature have a tendency to scratch on vertical objects as a way of marking their territory and to get rid of excessive dead tissue on their claws and the pads of their feet. One way to help overcome this habit is to get a scratching post and repeatedly make scratching motions on it with the cat's paws to encourage her to scratch where it's appropriate. The decision to have a cat declawed shouldn't be undertaken lightly: spend some time discussing the pros and cons of the procedure with your vet so you can make an informed decision.
RESOURCES :
The Penguins : Spheniscidae (Bird Families of the World)
Model: 019854667X
Author: Tony D. Williams
Oxford University Press
April 1995
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