Snow and Winter Ecology

Question 1

What are the 3 challenges organisms are presented with during the winter?

Answer 1

1. Balancing trade-offs of energy supplies with necessity to live and reproduce
2. Reduced access to food for animals
3. Reduced access to sunlight and water for plants

Question 2

How does winter affect the energy budget?

Answer 2

Species may need to delay reproduction and invest more energy into maintenance

Question 3

What are the 3 strategies of survival during the winter?

Answer 3

Migration, resistance, and death

Question 4

What is migration?

Answer 4

A strategy to avoid the maintenance associated with winter by avoiding winter altogether. An organism moves to more temperate conditions when snow and cold makes habitat unusable. However, it takes a lot of energy to migrate

Question 5

What is resistance?

Answer 5

Specialized traits to cope with winter.

Question 6

What is hibernation and torpor?

Answer 6

A state of reduced metabolic rate. Larger animals can store enough fat tissues to hibernate, smaller animals can only do torpor. Homeotherms can survive on stored energy, poikilotherms either tolerate being frozen (antifreeze substances) or avoid being frozen (going underground)

Question 7

What is acclimation?

Answer 7

Tolerance of cold temperatures changes with the seasons

Question 8

How is death a survival strategy?

Answer 8

Don’t have to put energy into maintenance, instead all an organism’s energy and efforts are put into one big reproduction event. Even though they die, their offspring are around and are resistant/dormant

Question 9

What is Bergmann’s rule?

Answer 9

Mammals and birds are larger at higher latitudes (larger animals hold more heat)

Question 10

What is Gloger’s rule?

Answer 10

Races of mammals and birds have lighter pigmentation in arid regions than related species do in humid regions

Question 11

What is Allen’s rule?

Answer 11

Appendages get smaller as latitude increases

Question 12

What are 5 morphological adaptations to cope with winter?

Answer 12

1. high foot surface to body weight ratio so the feet act like snowshoes
2. Long legs for deep snow
3. Production of glycol or proteins that stop ice formation in the cells
4. colour change
5. subnivial adaptations

Question 13

What are 6 behavioural adaptations to deal with winter?

Answer 13

1. migrate away from unsuitable snow conditions
2. using a food source above the snow
3. digging into the snow
4. specialized locomotion
5. trail-making
6. choosing a habitat with more suitable snow

Question 14

What is the subnivial zone?

Answer 14

The area beneath the snow