30 Life At The Poles

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LIFE AT THE POLES by LISA JO RUDY With the Editors of TIME FOR KIDS

CHAPTER 1 The Coldest Places on Earth The areas around the North Pole and the South Pole are the coldest places on Earth. They are very cold and far away. We are starting to learn more about them. One fact we do know is that some animals can live and grow in these two very cold places. Picture the Poles What are Earth's poles? They are places on the surface of Earth. Imagine a long rod, or stick, that goes through the middle of Earth. One end sticks out at the top of Earth. The other end sticks out at the bottom. When Earth rotates, it spins around the rod. The imaginary rod sticks out of Earth at the North Pole and the South Pole. The North Pole is at the "top" of Earth. The South Pole is at the "bottom" of Earth. This is because of the way Earth spins in space.

The Arctic The Arctic is the area around the North Pole. The Arctic is an ocean covered with ice. There is land around it, too. The salty seawater of the Arctic Ocean keeps some of the land warm. Forests can grow. There are lakes, and rivers. But most of the land is frozen and empty. In the middle of the Arctic Ocean is the North Pole. Antarctica Antarctica is the continent around the South Pole. There is frozen water around this land. Antarctica is a cold, dry, high, and windy place. Antarctica has big icebergs and giant mountain ranges, too. There is almost no life there. No humans live in Antarctica, but scientists spend time there. They study the area and the weather. They do many experiments. The South Pole is in the middle of Antarctica. Amazing Antarctica • Antarctica is the biggest desert in the world! It rains less than 5.08 centimeters (2 inches) a year in Antarctica. • About 90 percent of the ice in the world is in Antarctica. • The only animals that live in Antarctica all year are small insects, krill, other tiny living things, and penguins. • Whales, seals, and birds return to Antarctica in summer. • Antarctica is the only continent where human beings do not have communities.

CHAPTER 2 Adapting to Very Cold Weather The Sun never rises during the polar winter. It is cold and dark twenty-four hours a day. How do animals live through this cold, dark winter? Some mammals, insects, birds, and fish can adapt to the very cold weather in the Arctic. Penguins are the only animals that can live in Antarctica in the winter. Reptiles (snakes and lizards) and other animals do not live at the poles. They need a lot of sunlight to stay warm. Animals on the Move Some animals leave the Arctic in winter. They migrate. These animals return when there is food and sunlight. The Sun never sets at the poles in the summer. The Sun stays low in the sky. The air does not get very warm. The gray whale migrates from the Arctic. It swims south to Baja California to spend the winters. The arctic tern is a bird that migrates from the Arctic, too. It flies all the way around the world. Some caribou and reindeer migrate to the Arctic during the spring. These animals have hairs that trap air and protect them from the cold. These hairs also help them float when they move in water.

Sleeping Through the Winter Some animals find a warm place to curl up during the cold polar winter. Polar bears are deep sleepers. They hibernate. Arctic ground squirrels are hibernators. They sleep all winter long. Polar bears sleep for most of the winter. But they do not really hibernate. Sometimes polar bears wake from their sleep for a snack! Living with the Cold Whales and birds that live at the poles have a thick layer of fat, called blubber. This layer of fat keeps them warm. They have warm, waterproof feathers, or fur on top of their fat. Blubber, feathers, and fur allow these animals to survive at the poles. Some animals have other special traits that help them survive at the poles. Arctic and Antarctic insects and fish have special chemicals in their blood. These chemicals keep them from freezing. Antarctic krill are tiny shrimp-like animals that live in the cold Antarctic seas. These krill are food for whales, fish, squid, and other sea animals.