Deciduous Forest Animals
Animals and plants in deciduous forests have special adaptations to cope with seasonal climate changes, especially winter. Some animals survive cold winters by going into hibernation (dormant condition of some animals that sleep through the winter). There are degrees of hibernation ranging from deep to shallow. Animals, such as the ground squirrel that experience deep hibernation have large drops in body temperature as well as large, rapid drops in heart rate. A ground squirrel will retreat underground as winter approaches, reduce its body temperature drastically within a few hours, and become dormant (alive but inactive). During hibernation the squirrel's heart may beat only 10 to 20 times per minute (instead of from 200 to 300), and it may breathe only four times per minute (instead of from 100 to 200). Some animals, such as bears, badgers, raccoons, and opossums sleep in winter with little or no drop in body temperature, and their heart rate falls over a period of time. Bears of the northern forest may sleep for several months. Their heart rate may drop from 40 to 10 beats per minute and their body temperature remains normal. The bear will easily awaken if disturbed. Bears give birth during their hibernating period. Their higher body temperature during hibernation provides the energy needed for pregnancy, birth, and the nursing of young.
Some of the animals avoid the cold winters by taking part in migrations, which is a periodic movement of animals in response to changes in climate or food availability. Most bald eagles migrate south in the fall to warmer areas with sufficient food and return north in the spring to nest. Fledgling (young bird with feathers necessary for flight) bald eagles migrate before their parents. How these young birds know when and where to travel is not known. Why some return to their point of origin and others do not is another mystery.
Some animals in deciduous forests have physical adaptations that allow them to stay in the forest and stay awake during the winter. For example, large deer that live where the weather gets cold have bodies that can hold heat (energy that is transferred from a warm material to a cool material) for a longer time than other animals. Wolves grow a thicker coat of fur during the fall to keep them warmer in the winter. This extra hair is shed during the warmer seasons.
In areas where it snows in the winter, some animals, such as rabbits and weasels, have a change in fur color twice a year. For most of the year, the fur is brown, which blends in with the colors of the forest and helps the animal to hide from predators. But in the winter the fur is white so it blends in with the snow. The animals' fur color changes automatically, and this change is controlled by the amount of daylight there is per day. As the number of daylight hours decreases, the dark fur is shed and the new fur is white.
To demonstrate how monarchs glide in flight.
- sheet of copy paper
- black marking pen
- 1 paper clip