Hibernation
is one of many adaptations to the cold and decreased food supplies
of Iowa winters. Most mammals, including people, tend to slow down a little
during the winter. True hibernators actually curl into a tight ball and reduce
to extremely low levels their heart and breathing rates, body temperature, and
metabolism. They need less food to survive. Bats which eat insects have
virtually nothing available to eat so they are forced to hibernate all winter.
Other hibernators include woodchucks, ground squirrels, jumping mice, and a few
other rodents. There are a number of mammals such as badgers, raccoons,
chipmunks, and skunks which do not truly hibernate. They do, however, reduce
their need for food by sleeping deeply for periods extending from a few days to
two weeks.
As winter arrives in Iowa, many wild animals depart or
hibernate. Birds which feed on non-dormant insects and worms or need open water
migrate as the food disappears and the water freezes. But many birds,
especially those that feed on seeds or dormant insects, remain in Iowa. Covered
with great feathery insulation and equipped with a high metabolism that burns
like a small furnace, these species are able to endure Iowa’s sometimes brutal
winters. They exist wherever there is accessible food, adequate shelter, and a
ready source of water. Where these requirements are met, birds are often the
most visible and animated spectacles of winter.
Have students create a news cast in which they pretend to
interview a just emerged hibernator. In a written script or in an audio recording,
they can ask questions about the animals’ winter experiences and its plans for
the coming warm weather.
Animal Antifreeze
Materials:1 film canister with a lid for each participant; thermos (1 quart) of liquid knox gelatin (will be enough for 20 participants); suitable habitat
- Explain that a hibernating animal (chipmunk) or winter sleeper (bear) must select a sleeping spot that will provide protection from the winter cold. If the temperature of the sleeping spot falls too low, the sleeping animal may freeze to death.
- Each participant is given an “animal”(a film canister), ask them to pop the head off (the lid) and fill the animal with “blood” (liquid knox gelatin from the thermos).
- The participants job is to find a suitable shelter – sleeping spot that will protect them from freezing over the winter months. Explain that burrowing and building with nonliving materials is permitted. Define the boundaries before sending the group out. Give the participants five minutes to select sleeping spots for their animals.
- The number one rule of this activity is not to lose their animal – they must remember where they put their animal.
- After all “animals” have found their resting spot…lead the group on a winter hike.
- Winter hike topics too include: good over wintering habitat for the animals; hibernation/migration; animal food (acorns, insects, plants/twigs); animal tracks in the snow
- After a 40 to 45 minute hike return to the spot where the “animals” were hidden.
- Send the participants out to retrieve their animals.
- Have them “pop” the head (the lid) off of their animals and see whose animal survived and who froze (solid gelatin).
- Have the survivors explain where and what they did to help keep their animals from freezing. Lead a group discussion on how more animals could have survived. Or other items that would have been helpful, i.e. an animal fur to wrap around the container, put in area away from the wind, hide deeper in a log or hole in a tree, etc… some individuals may have decided just to carry their animal during the hike. These are all good “adaptation” strategies for a group discussion.
