Class type: Elective
Time: 1-3 hours
Optimal season: Winter
Materials: No special materials needed.
Expected outcomes:
The student will gain a basic understanding of:
1. what causes the winter season and how its intensity varies with latitude and
elevation.
2. the main problems that winter cold presents to plants and animals.
3. a variety of strategies used by organisms to overcome these problems,
including hibernation, migration, and storage of food (animals) and dropping of
leaves or overwintering as seed or underground (plants).
4. the advantages to some plant species of decreased competition for light in
winter and early spring, including forest-floor evergreen species, spring ephemeral
herbs, winter annuals.
5. ideas for wintertime nature study.
The Course:
1. Winter, season of cold and short days
a) What causes winter (tilted earth means diminished sunlight)
b) Winter, elevation, and latitude
c) Winter and erosion
d) Problems winter presents for living things
- Desiccation (ice is not available to plants and animals)
- Freezing (ice crystals in cells cause fatal physical damage)
- Diminished food supply
- Diminished oxygen in ponds (ice cuts off air, snow cover prevents oxygenating photosynthesis in aquatic plants)
2. Adaptations of plants to winter
a) Deciduous trees (both leaves and sap fall)
b) Increased light on deciduous forest floor (evergreen herbs and spring
ephemerals)
c) Resisting drying (e.g., curling of Rhododendron leaves)
d) Overwintering as seeds, underground parts, winter annuals, woody stems)
3. Adaptations of animals to winter
a) Hibernation and less profound states of torpor
b) Hoarding food
c) Migration (sometimes combined with hibernation, e.g. bats and monarch
butterflies)
d) Insulated nests, thicker fur, huddling together
e) Change of diet
f) Change of color in a white and brown world (e.g., snowshoe hare)
g) Mixed foraging flocks of birds
4. The naturalist in winter – things to observe and things to do (e.g., bird nests,
animal tracks and signs, woody plants, terrestrial invertebrates, etc.)
