Introduction to Penguin
Penguin, a large, flightless sea bird. There are 17 species of penguins, belonging to six large genera (groups). The various kinds differ in size and the markings on heads and necks, but are otherwise similar in appearance. Male and female of a species look alike. The smallest penguin, the little blue penguin, reaches a height of about 12 inches (30 cm); the largest, the emperor penguin, reaches 39 inches (1 m). Penguins are normally quiet birds; when excited, however, they make raucous croaking or trumpeting sounds. The jackass penguin is named for its loud, braying call.
Penguins guard their chicks until they can fend for themselves.How Small Is the Smallest Penguin?The little penguin got its name because it’s the smallest penguin of all. It stands only about 12 inches (30 centimeters) tall and weighs about 2 pounds (1 kilogram).
Little penguins live in dunes on the shores of Australia and New Zealand. They stay in burrows along the coast. They can build their own burrows, but they also use natural cracks in rocks or old nests left by other birds. Each day they leave their burrows behind to hunt for food at sea. At dusk, they return to land and crawl back into their burrows.
Penguins are blue-gray, midnight blue, or black on their upper parts, and white below. Their heads are usually black, with bold white markings. Rockhopper penguins are distinguished by yellow plumes on top of their heads. Penguins have short necks, thickset bodies, and short tails. Most of them have short, blunt bills; emperor and Adélie penguins, however, have longer, pointed, down-curving bills. Penguins' short legs and webbed feet are so far back on their bodies that they stand erect when on land. Their bodies are covered with three dense layers of short feathers.
How Did Rockhoppers Get Their Name?Rockhoppers got their name because of the way they hop up steep, rocky slopes. These penguins hop up the slopes with both their feet together. Many rockhoppers live in the rocky Falkland Islands, off the southern coast of South America. People there call them “jumping jacks.”
Rockhoppers need to hop because they nest up to 500 feet (150 meters) above the sea. Having nests up high keeps rockhoppers safe from leopard seals, which often hunt these birds near the shore. Luckily for rockhoppers, leopard seals aren’t good climbers.
A rockhopper’s head is very colorful. This bird has a bright orange-red bill, a yellow crest, and red eyes. A rockhopper weighs about 6 pounds (3 kilograms) and stands about 22 inches (56 centimeters) tall.
Penguins inhabit the coasts of Antarctica, the southern coasts of Africa and Australia, and the coast of South America as far north, in the west, as Peru. They are also found in New Zealand, the Falkland Islands, and numerous small islands in the colder regions of the southern Atlantic and Pacific oceans. The Galápagos penguin is found in the Galápagos Islands, on the Equator. This species is endangered because of human encroachment on its food supply and nesting grounds.
The name penguin was once given to the great auk, an arctic bird now extinct. The great auk was not related to the penguin but was similar in appearance.
Habits
Penguins walk with a clumsy waddle. When traveling on ice, they often throw themselves down on their bellies and slide. In water, penguins are swift and graceful. They swim with their flipperlike wings, using their feet as rudders. Some can swim at a speed of more than 20 miles per hour (32 km/h). Penguins can dive to great depths. The emperor penguin can dive the deepest—to depths of more than 1,700 feet (518 m). Some penguins stay at sea for weeks at a time. Penguins eat only when at sea, feeding on fish, squid, and such crustaceans as shrimp.
Penguins swim with their flipperlike wings, using their feet as rudders.Penguins are sociable birds, gathered by the thousands in small nesting areas. The females lay one or two white or pale-green eggs. Most species lay their eggs in crude nests on the ground or in burrows. The nests may be built of smooth stones or lined with sticks or grass. Male and female usually take turns incubating the eggs—a period varying from 30 to 60 days according to the species—and caring for the young. While incubating its eggs, a penguin does not eat. Most penguins return to the same mates every year.
Emperor penguins, which breed in the Antarctic, do not build nests but lay their eggs on the bare ground or ice. They incubate their eggs by carrying them on their feet, protected by a fold of skin. The emperor is unique in some of its breeding habits. The female turns her single egg over to the male a few hours after she lays it. The male incubates it for the entire period of about two months. He is able to fast by living off a reserve store of fat. The emperor is the only bird that breeds and incubates its eggs in the Antarctic winter. Temperatures during this period often fall to -60° F. (-51° C.).
What Do Penguins Eat?Penguins find all their food in the sea. They eat mostly fish and squid, which they catch in their sharp beaks. They also eat crustaceans (kruhs TAY shuhnz), such as crabs, shrimp, and krill.
When a penguin is at sea, it usually eats as much as it can. A large penguin can collect up to 30 fish in one dive. That’s a big dinner!
Since they don’t have teeth, penguins use their beaks to grab and hold wriggling prey. Spines on the roof of a penguin’s beak help this bird get a good grip on its slippery food. Penguins even have spines on their tongues.
Penguins swallow pebbles and stones as well as their regular food. Why? Even scientists aren’t sure of the main reason. The stones may help penguins grind up and digest their food. And the stones may add enough extra weight to help penguins when they want to dive down deep.
Are All Penguins Black and White?All adult penguins have dark backs and white or yellowish-white fronts. Their dark backs are usually black. However, their beaks, necks, and feet may be brightly colored. Some penguins also have colorful crests of feathers on their heads.
A penguin’s coloring comes in very handy. It camouflages (KAM uh flahzh uhz) the bird, or helps it blend in with its surroundings. A school of fish swimming above a penguin may not even notice the bird. That’s because the penguin’s dark back blends in with the dark waters below it. An enemy or prey may not see a penguin swimming above it either. That’s because the penguin’s pale belly blends with the bright light of the sky or ice above it.
A penguin’s dark back may also keep it from getting too cold. Dark colors soak in, or absorb, sunlight. Scientists think penguins may use their backs to get warmer when they float on their stomachs in cold seas.
Locomotion
What Are Penguin Wings Good For?Penguins have very stiff wings that are sometimes called flippers. Like other flightless birds, penguins can’t use their wings to fly. But they can use them to swim.
Other parts of a penguin’s body are made for swimming, too. In fact, even the shape of a penguin helps it swim. A penguin’s body is shaped like a torpedo. With a body shaped like that, a penguin can easily cut through the water. A penguin also has strong, webbed feet and a stubby tail. It uses its feet and tail as a rudder to steer through the water.
As swimmers, penguins are strong and fast. They usually swim at about 8 miles (13 kilometers) per hour. At this speed, they can travel great distances. In short bursts, they can reach three times that speed.
How Do Penguins Dive Really Deep?Penguins flap their wings, or flippers, to dive deep. Most other diving birds use their feet to push themselves through water. Birds that dive using their feet don’t usually go as deep as penguins do using their flippers.
An emperor penguin can dive deeper than any other bird. It can go down as deep as 1,750 feet (530 meters). That’s deeper than the height of the tallest building in the world. When diving, an emperor penguin can hold its breath for nearly 20 minutes.
This superb diver is also the largest of all penguin species. An adult emperor can be just over 4 feet (1.2 meters) tall and weigh around 85 pounds (38 kilograms).
Why Do Penguins Swim Together?Penguins spend some of their time on land or on huge slabs of ice. But when they need to eat, they must return to the water. Most kinds of penguins, like Adelie (AD uh lee) penguins, return to the water in groups. That’s because an enemy, such as a leopard seal, may be hiding below the water’s surface. A group has more eyes to look out for an oncoming predator. And a nearby predator may have a hard time choosing which penguin to chase. A lone penguin is a much easier target.
Penguins have other enemies in the water to worry about besides leopard seals. Sea lions, sharks, and killer whales all prey on penguins.
On land, adult penguins are usually safe. But chicks that are weak, sickly, or left alone are always at risk of being attacked. Large birds of prey, gulls, and giant petrels eat penguin chicks if given the chance.
Can Penguins Breathe Underwater?No, they cannot. Penguins don’t have gills for breathing underwater as fish do. Instead, penguins have lungs—just as people do. That means that they must come to the surface to breathe air.
When penguins need to breathe, they often leap clear out of the water. If they are traveling long distances, they might leap up about once a minute. But if they are fleeing from an enemy such as a leopard seal, some penguins leap clear out of the water every few feet. Besides allowing them to breathe, leaping helps penguins keep away from their enemies down below.
Being able to leap also comes in handy when a penguin needs to get onto ice or land. Most penguins can’t pull themselves out of the water onto an icy ledge or a rocky shore with just their flippers. So they leap instead.
How Do Penguins Move About on Land?Penguins have a few ways of moving about on land. One way is walking—or waddling! Penguins have bodies that are ideal for swimming, but not for walking. Penguins have tall bodies and short legs. This odd combination makes them rock from side to side when they walk. Penguins usually waddle slowly. But when penguins are in a hurry, they can waddle for short distances as fast as a running human.
Some penguins, such as rockhoppers, are good climbers, too. Often, the slopes they climb are icy and steep. But penguins can get a good grip because they have hooked toes. Sometimes penguins even use their bills to get better holds on the rock or ice.
Tobogganing, or sledding, is another way that some penguins move about on land. The emperor penguins you see here are tobogganing over ice and snow on their bellies. They “row” with their flippers and push with their feet.
How Do Penguins Stay Warm and Dry?On top of their skin, penguins have thick coats of feathers. Penguin feathers are good at trapping heat. They are the main reason some penguins can live in such cold places. The feathers are also waterproof. They keep penguins dry underneath, even while the birds are swimming.
If penguins don’t keep their feathers in very good shape, they don’t stay waterproof. So penguins spend several hours a day preening, or caring for their feathers. Penguins use their beaks, flippers, and feet to preen. For extra protection in the water, penguins spread oil on their feathers. The oil comes from a special gland near their tail feathers.
Penguins that live in cold regions have an extra layer of fat, called blubber. The extra layer of fat acts like a blanket to help keep the birds warm when the temperature drops. Penguins also use fat to store energy. That comes in handy when they go long periods without food.
Why Do Penguins Shed Their Feathers?Penguins shed their feathers because they become worn and damaged. When penguins shed their old feathers and grow new ones, it is called molting. Penguins molt once a year.
Penguins always molt on land or on ice. Until they grow new waterproof coats, they can’t go back into the water. And the water is where they need to go to find food.
Sometimes penguins might have to go for more than a month without food while they molt. To prepare, penguins eat as much as they can during the weeks leading up to the molt. Eating so much helps them add fat to their bodies. The penguins live off the fat while they grow new feathers.
Penguin Social Life
What Is a Penguin Colony?Once a year, large groups of penguins return to the land at the same time. They do this to mate and to lay their eggs. Most penguins make their nests in huge gatherings called colonies. A penguin colony may have thousands of members. In fact, a colony of Adelie or king penguins can have 200,000 pairs of penguins.
Penguins usually form colonies close to where they themselves were born. And it doesn’t matter how far away from “home” some penguins are when it’s nearly time to mate. Sometimes they return thousands of miles across the open sea to get there.
How Do Penguins Build Their Nests?Usually, both male and female penguins work together to build a penguin nest. First, the mates must claim a good spot. In the crowded colonies, this is not easy. Predators are more likely to hunt for eggs and chicks on the edge of a colony. So the good spots are in the center of the nesting grounds.
To make their nests, most penguins dig small holes under large rocks or bushes. Penguins near the South Pole can’t dig their nests because the earth is frozen. So they build nests of pebbles on the ground. King and emperor penguins don’t build nests at all. They carry their eggs with them on their feet wherever they waddle!
What Does It Take to Hatch Penguin Eggs?Penguin eggs need time and warmth to hatch. Most female penguins lay two eggs. Penguin eggs take 30 days or longer to hatch. The females of larger species, such as king and emperor penguins, lay only one egg. It needs over 60 days to hatch.
Until they hatch, penguin eggs have to stay nearly as warm as an adult penguin’s body. Most penguins sit or lie on top of their eggs to keep them warm. This is called incubation (ihn kyuh BAY shuhn). A king or an emperor penguin incubates its lone egg on top of its feet. A special fold of skin covers the egg to keep it warm.
In most species of penguins, both parents take turns looking for food and incubating. But with emperor penguins, the males do all the incubating. Since penguins can’t eat while they incubate, male emperors go without food during this period. It may be 65 days before males can return to the sea and eat.
What Are Penguin Chicks Like?Baby penguins don’t look like their parents—they look more like puffballs! Fuzzy coats of feathers, called down, cover the chicks from their heads to their feet. As the chicks grow older, they lose their fluffy feathers. Over time, they grow adult feathers.
Parents must guard their chicks until they are strong enough to protect themselves. Penguin parents pass food they’ve partly digested to their chicks with their beaks. It’s easier for the chicks to swallow food “served” like this.
Some kinds of penguin chicks stay at their nests for just the first two months of their lives. Others stay near the nest up to a year. The parents don’t guard them the entire year, but they do feed them. When young penguins are old enough, they leave the colony and learn to feed themselves at sea. Most return to land only to molt and to nest.
Do Penguins Make a Lot of Noise?Yes! Penguins in a colony can make a lot of noise when they call to one another. Calling is important because parents and chicks can recognize each other by their voices. Without their calls, penguin families could easily lose track of each other in such crowded places.
Nearly every bird species has its own special calls, and so does each kind of penguin. Some penguin calls sound like the cackle of a hen. Some boom like a trumpet. Others even have a harsh cry that sounds like the braying of a donkey!
Penguins communicate in other ways, too. They may wave their heads and flippers. Sometimes they bow. When penguins fight for nesting spots, they may try to stare down one another. They also point at each other with their beaks. If one penguin just isn’t getting the message, another penguin may even charge.
Penguins make up the family Spheniscidae. The little blue penguin is Eudyptula minor; the emperor, Aptenodytes forsteri; the jackass, Spheniscus demersus; the rockhopper, Eudyptes crestatus (or E. chrysocome); the Adélie, Pygoscelis adeliae; the Galápagos, S. mendiculus.