Research Simulation-Life in a Deep Freeze ** PARCC PRACTICE
No due date
Read the article “Life in a Deep Freeze.” Then answer the questions. Life in a Deep Freeze by Sandra Markle
How do animals survive the Arctic’s c-c-cold winters?
1 It’s noon and dark and very cold—minus 30°F. Snow and ice blanket the region. Strong winds blow across ice-covered ocean waters. It’s winter in the Arctic, one of the harshest environments on Earth. But, for many animals, this place is home.
2 So just where is the Arctic? It’s about as far north as you can go. It’s the North Polar region—the Arctic Ocean plus the lands bordering it. The landscape varies from high, icy mountains to tundra. That’s a treeless plain where a layer of soil remains frozen all year. Arctic animals have adapted well to their surroundings with some rather clever survival tactics.
3 Some Arctic animals have found clever ways to wait out the long, harsh winters.
4 Grizzly Bear: This bear spends all spring, summer, and fall eating and storing up fat. Then the bear goes into a special type of sleep. During its winter sleep, the grizzly lives off its stored fat. To conserve energy, the bear’s internal temperature drops a few degrees. Its heart rate slows down too.
5 Collared Lemming: This furry relative of mice and rats changes its coat from grayish brown to white in winter. It also grows longer front claws. With their claws, lemmings dig tunnels under the wind-packed snow. There they live, protected from the cold and their predators.
THE LAYERED LOOK
6 For some animals, being fat means staying alive. That’s especially true for animals that hunt and live in the icy waters of the Arctic Ocean.
7 Walrus: This animal keeps warm even while digging for clams along the bottom of cold ocean waters. Under its inch-thick hide, the walrus has a nearly six-inch layer of blubber, or fat, to block out the cold. During deep-sea dives, warm blood shifts away from the skin surface to inside the body. This helps the walrus keep its body heat stable at about 99°F. When the walrus moves ashore, blood flows back to the skin.
8 Harp Seal: Protected by a thick layer of blubber, the harp seal spends most of its time in icy waters. The seal is a fast swimmer and can stay underwater for 30 minutes at a time. Its speed in the water allows it to escape its predator, the polar bear. In late winter, females climb onto a chunk of ice to give birth. A seal pup is born with a white, fluffy coat, but no blubber. The pup keeps the coat until it develops a layer of blubber. And that happens fast. On a diet of fat-rich mother’s milk, a pup can gain over 80 pounds in just three weeks.
DRESSED FOR WINTER
9 Like you, many Arctic animals change their coats with the seasons. In winter these animals replace their summer coats with thicker ones to keep them warm when temperatures plunge. They’ll wear their winter coats for a long time. Arctic winters can last for eight months.
10 Arctic Hare: The arctic hare living in the northernmost part of the Arctic stays white all year. But its fur coat grows thicker and longer in winter. The hare has small ears, which protect it too. Can you figure out how? Less skin is exposed to the cold, and small ears lose less body heat than larger ears.
11 Musk Ox: This animal has lots of hair to keep it warm. In fact the native Inuit people call it umingmak, meaning “the animal with skin like a beard.” The musk ox’s shaggy outer coat covers everything but its feet. Underneath this outer layer of long, coarse hair is even more hair—a soft, woolly coat. The musk ox sheds this undercoat when the weather gets warmer. Musk oxen also have curved hooves with sharp rims. That gives them solid footing on icy slopes.
12 Snowy Owl: Feathers keep this bird warm. The snowy owl’s entire body—even its legs and toes—is covered with soft, fluffy feathers. On top of this coat is still another coat of overlapping feathers. When temperatures drop, the owl crouches on the ground behind an object that can block the wind. The owl stays still. Flying would use up precious heat energy.
13 Arctic Fox: As winter approaches, the fox replaces its brown summer fur for a longer, heavier snow-white coat. The new coat keeps the fox warm as well as hidden from predators, like the wolf. A special bloodflow system helps the fox hang onto its normal body temperature. Warm blood flowing toward the fox’s legs heats up the cool blood returning from its feet. That means that the arctic fox has a warm body and cold feet. Having cold feet helps too. Ice doesn’t stick to cold toes.