Penguins Essays - Flightless Birds, Penguins, Neognathae, Biota

Penguins Essays - Flightless Birds, Penguins, Neognathae, Biota Penguins I They are small white and black bird like creatures that live in cold regions. Penguins are the most fascinating creature around. II Explanation 1 Physical characteristics A Most penguins have a white breast and a black back and head. Many species exhibit red, orange, or yellow patches on the head and neck. Because their short legs are placed far back on their bodies, penguins assume an upright posture. B Penguins are grouped into 18 species and 6 genera, most of which are found in Antarctica and on subantarctic islands. Others are native to the coasts of Australia, South Africa, and South America and to the Galapagos Islands. C The largest species are the king penguin, from 36 to 38 inches in height, and the emperor penguin, which may attain a height of more than 48 inches. Both species are found on the Antarctic ice barrier. The king penguin is also found in Tierra del Fuego and on eight islands in the southern hemisphere. The smallest penguin is the little blue penguin of Australia and New Zealand; its height is 16 inches or less. Unlike most species, the king, emperor, and little penguins have blue-gray backs. Another distinguishing feature of the king and emperor penguins is the presence of bright reddish or pinkish shields on the sides of their mandibles and large orange or yellow patches on the sides of their necks. D Although descended from flying ancestors, penguins have become highly specialized for swimming; their stiffly held wings resemble the paddles of other swimming vertebrates. Penguins do not have specific feather tracts, as do most birds, but are covered almost uniformly with small, scalelike feathers. Whereas most birds shed their feathers and grow new ones during a relatively long period of the year, penguins molt all of their feathers and, in some species, even shed the shields from the beak within a short space of time. A molting penguin has a swollen, untidy appearance; it loses its feathers in huge patches as new feathers appear. During the molting period, which may last several weeks, the penguin does not enter the water to feed. 2 The cold A The ability to withstand intense cold is one of the penguin's greatest assets. Most penguins have rather small feet, wings, and heads; the relatively little surface area which results in excellent heat conservation. In addition, many penguins have a thick insulating layer of fat under the skin. Some species are better equipped for cold weather than others. The emperor penguin appears to be the best equipped of all. 3 Walking A Penguins usually walk or hop and toboggan along on their breasts, pushing with wings and feet. They swim with great speed and agility. The flippers are their sole means of propulsion; the feet are used for steering. Some species progress by purposing, which is swimming underwater some distance, emerging in a graceful arc to take a fresh breath, and submerging again. Penguins feed on fish, cuttlefish, crustaceans, and other small sea animals. 4 Flocks A Penguins are gregarious birds and are found in flocks even at sea. On land the colonies often number in the hundreds of thousands. Although the birds have suffered greatly at the hands of humans, who have slaughtered great numbers for their blubber and, more recently, for their skins, the inaccessibility of the Antarctic region has helped preserve the group. Natural enemies of the penguin include leopard seals, killer whales, and, in the case of young chicks and eggs, skuas. III Conclusion Penguins are wonderful gentle creatures. I hope you like them as much as I do.