Activities: A Long Winter's Nap
Suggested Grades 2-6
Coping with seasonal changes in temperature and precipitation
Hibernation, torpor, dormancy, estivation, diurnation
What are some of the ways that frogs and other animals adapt to winter?
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.
After completion of this activity students should be able to describe
ways in which frogs adapt to seasonal changes
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.
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
What do frogs do to survive in the winter?
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.
Click here for more information on how this activity correlates with standards.
6 Science Application (Living Systems)
Content Standard C Life Science (organisms and environments)
Strand 2.2 The Living Environment
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