Cold Environment Living

Question 1

Hibernation

Answer 1

State of extended torpor in which metabolism and physical activity is significantly slowed.

Question 2

Examples for hibernation

Answer 2

Ground squirrels (Urocitellus sp.)
Bats (Myotis sp.)
Some birds, eg. common poorwill (Phaelanoptilus nuttali)

Question 3

Metabolic suppression

Answer 3

90% of metabolism is deemed non-essential and temporarily stopped.

Question 4

Metabolic suppression example

Answer 4

Arctic ground squirrel (Urocitellus parryci) lowers body temp to 2.9*C, relying on supercoolant proteins to prevent ice crystals.

Question 5

Thermoregulation

Answer 5

Arousals in hibernation can briefly increase metabolism and body temp, allowing body to recover slightly.

Question 6

Energy storage of hibernation

Answer 6

Brown adipose tissue (BAT) is metabolized during hibernation through non-shivering thermogenesis.

Question 7

Example for BAT

Answer 7

Bears (Ursus sp.) use BAT to sustain themselves at a heart rate of 8bpm.

Question 8

Behavioral preparations for hibernation

Answer 8

These begin after summer solstice, can be eating as much as possible, den construction.

Question 9

Burrow making example

Answer 9

Woodchucks (Marmota monax) dig deep, 6ft, burrows.

Question 10

Hibernation strategies

Answer 10

Metabolic suppression
Thermoregulation
Physiological adaptations
Behavioural adaptations

Question 11

Non-hibernation strategies

Answer 11

Thermoregulation
Insulation
Behavioural strategies

Question 12

Thermoregulation non-hibernation example

Answer 12

Chickadees (poecile sp.) shiver skeletal muscle to generate heat.

Question 13

Insulation non hibernation example

Answer 13

Arctic (Vulpes lagopus) fox has a winter coat

Question 14

Huddling non-hibernation example

Answer 14

Emperor penguin (Aptenodytes forsteri)

Question 15

Behavioural strategies non hibernation example

Answer 15

Polar bears (Ursus maritimus) build snow burrows for giving birth.

Question 16

Species specific example for small animal

Answer 16

White footed mice (Peromyscus leucopus) only employ torpor on particular tough days, but for most of winter are active.

Question 17

Species specific example for large animal

Answer 17

Musk ox (Ovibos moschatus) have long dense fur to minimize heat loss.

Question 18

Allens rule

Answer 18

Cold-adapted species tend to have shorter extremities (ears, tails, limbs) to minimize heat loss and conserve body warmth.

Question 19

Bergman’s rule

Answer 19

Warm-blooded animals in colder climates tend to have larger body sizes, which reduce heat loss due to a lower surface-area-to-volume ratio.

Question 20

Hormones involved in inducing hibernation

Answer 20

Melatonin, leptin and insulin.