Viatouch Teacher Articles
Science

Feathered Fish
by Anjali Amit

The sailors, who set out on the great voyages of discovery, rounding the Cape of Good Hope and Terra del Feugo, were probably the first Europeans to spot penguins. They were confused at the sight. Were these strange creatures fish or fowl? They called them "feathered fish."

We now know that penguins are birds. They are covered with feathers. Penguins have about seventy feathers per square inch, more than most flying birds. But they cannot fly.

There once was a time when penguins did fly. They were much smaller then like the puffins of today; and, their wings could work well in both air and water. However, a flyer needs wings with a large surface area to catch the air and to provide lift as well as motion. Thus over the course of 65 millions years, penguins began losing their ability to fly.

Picture an eagle gliding, wings spread wide. Such wings do not work well in the seas. Imagine two sheets of paper: one flat, the other folded up. The more compact a thing is, the more easily it moves through the water. Many millennia ago when penguins forsook the skies for water, they evolved to become expert swimmers. Their wings became smaller, more paddle-like flippers. These flippers gave penguins the ability to dive deeper and to swim faster than any other bird.

The loss of wings does not mean that penguins are aquatic creatures only. They can walk, but the masters of water become clowns on land. Penguins have to lean forward to maintain their balance. They waddle because their legs are set far back. This adaptation makes their legs efficient rudders—these birds are streamlined-swimming machines. Yet regardless of their swimming prowess, some species have to walk long distances. For example, the Emperor and the Adelie penguins set their rookeries far from the shore. Therefore, instead of walking the 90 - 100 miles to the nutrient-rich waters they toboggan—belly flop to slide along.

Though penguins spend most of their time underwater, they are oxygen-breathing birds that have to come up to breathe. They do this by leaping out like a porpoise for a gulp of air. In fact, they've adapted so well to their chosen environment that penguins have learned how to stay underwater for longer periods. They lower their core temperature from 102°F to 52°F. Thus they burn less oxygen, and can stay down longer.

Penguins are found in all the southern continents from Antarctica to the equatorial waters. The outer feathers are waterproof. To stay warm, the inner layer of down traps the warm air in. To cool off they ruffle their feathers and hold out their flippers, or stretch out and let the heat escape through their feet. Whether it's the icy Antarctic or the warm equator, these "feathered fish" that we call penguins have excellently adapted to handling extreme temperature ranges.



Bibliography

Fletcher, Neil. Penguins: See How They Grow. NY: Dorling Kindersley, 1993.

Guiberson, Brenda Z. The Emperor Lays An Egg. NY: Henry Holt and Company, 2004.

Kalman, Bobbie. Penguins. NY: Crabtree Publishing Company, 1995.

Lynch, Wayne. Penguins! Ontario: Fireflies Books Ltd., 1995.

Internet:

http://42explore.com/penguin.htm
http://www.eliasdesigns.com/penguins/history.htm
http://www.gdargaud.net/Antarctica/Penguins.html
http://www.mbayaq.org/efc/efc_splash/splash_about.asp

Anjali is a children's book author whose first book,"Folk Tales From Rajasthan", was published when she was in college. Upon graduation she "sold her soul to Mammon"—went to work for a bank. She writes fiction, non-fiction, and edits technical documents. Her articles have appeared in various magazines. "Bedtime Stories from Around the World", her second book, was published a few years ago.