Stress

Question 1

Adrenocortical response

Answer 1

Hypothalamus -> corticotropin releasing factor -> pituitary gland -> adreno-corticotrophic releasing hormone -> adrenal Cortex -> glucocorticoids

Question 2

Natural selection on stress response example

Answer 2

Marine iguanas have been without predators for 5-15 million years, cats and dogs last 150 years. On islands with no predation iguanas are not wary and predators can get very close. Flight initiation distances are greater on islands with higher predation and HPA response is also greater on islands with predation

Question 3

Adaptive stress response to predators example

Answer 3

Belding squirrel produce different alarm calls for different types of predator. Trill for for terrestrial and whistle for aerial. Lab reared individuals only elicited a high CORT response to trills

Question 4

Anthropogenic environmental change on stress responses examples

Answer 4

Blackbirds in the city have a reduced stress response to humans to humans through selection or habituation

Hoatzin chicks have lower survival rates in areas of ecotourism - juveniles that have been exposed to tourists have elevated corticosterone levels, chicks are more likely to jump from nests