Learning Activities: A Long Winter's Nap
Suggested Grades 2-6

Concepts
Coping with seasonal changes in temperature and precipitation
Hibernation, torpor, dormancy, estivation, diurnation

Time
20-30 Minutes

Catalyst Question
What are some of the ways that frogs and other animals adapt to winter?

Background
Frogs are found all over the world in every type of habitat from the Arctic Circle to tropical regions, from deserts to rainforests. In order to survive these diverse conditions, frogs use several coping mechanisms. The first of these, hibernation, is a response to cold winters. The frog finds a place that is protected from the weather and predators. Its metabolism slows down and it lives off of energy that is stored in the body. Some frogs dig deep holes into the soil below the frost line. The spring peeper and wood frog find cracks in logs or rocks. These frogs are not as protected from the weather and they might actually freeze. The frogs are able to survive due to the large amount of glucose in their vital organs that serve as a sort of antifreeze. The leopard frog and American bullfrog spend the winter underwater. They reach a state called torpor. Torpor is a state of mental and motor inactivity with partial or total insensibility. It is characterized by extreme sluggishness but is not a total slow down of body functions like that which occurs during hibernation. The underwater frogs lay on top of the mud in oxygen-rich water and may even occasionally swim around slowly. Sometimes torpor is a short-term solution for an intermittent period of cold weather. Diurnation occurs when a frog goes into a state of torpor at night when it is cooler but is more active during the day.

Estivation is a reaction to diverse environmental conditions such as drought. Frogs like the African bullfrog dig deep into the soil just like during hibernation and become dormant. They then shed several layers of skin. This forms a waterproof cocoon that leaves only the nostrils exposed to the air. The frog can survive in this manner for a period as long as seven years if necessary. The frogs free themselves of the skin layers when moisture returns. In fact, the cocoon of skin might be their first meal after precipitation returns to the area.

Objectives
After completion of this activity students should be able to describe ways in which frogs adapt to seasonal changes

Materials
Chart paper
Markers
Pencils
Paper

Procedure
1. Have students make a chart comparing how they act and feel during winter, and how they act and feel during summer.

Example: Summer Outside most of the time Wear few clothes Winter Outside some of the time Wear heavy clothing

2. Discuss the changes that humans make for different seasons and the ways that animals respond to winter.

Evaluation/Review Questions
What changes do humans make during the seasons?
Why might you have different emotions during various times of the year?
What are some of the survival techniques that animals use to respond to winter?
What do frogs do to survive in the winter?

Extensions
Have students research climate and seasonal behaviors of anurans. What research has been conducted on the freezing of frogs? What is torpor? What are dormancy, estivation, and diurnation? Which other animals use these same responses?

References and Resources
Stebbins, Robert C. and Nathan W. Cohen. 1997. A Natural History of Amphibians. Princeton, NJ: Princeton University Press.

Oldfield, B. and J. Moriarty. 1994. Amphibians and Reptiles of Minnesota. Minneapolis, MN: University of Minnesota Press.

Internet Resources
http://www.alienexplorer.com/ecology/m27.html
http://cgee.hamline.edu/frogs

Education Standards
Click here for more information on how this activity correlates with standards.
Minnesota
6 Science Application (Living Systems)
National
Content Standard C Life Science (organisms and environments)
Environmental
Strand 2.2 The Living Environment

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