Flashcards in Stress And Behaviour 10 Deck (17)
What are some examples of stress and unpredictability in the environment?
Drought and extreme weather events
What are some predictable factors that animals can prepare for to prevent stress?
What is the emergency life history stage?
If an animal experiences a severe perturbation it can abandon its normal activities and enter a coping state until the perturbation ends
What is allostasis?
The process of maintaining stability- refers to mechanisms maintaining homeostasis
What does allostatic load refer to?
The increased workload needed to maintain stability in response to perturbation
Measured by overall energy expenditure
What happens if allostatic overload is reached?
The emergency life history stage is triggered
What is predictive homeostasis?
Values associated with predictable day to day and seasonal activities- the normal range when there is no particular threat
What is reactive homeostasis?
The values encountered in response to unpredictable changes in the environment- when the animal reacts to a threat
What is homeostatic failure/homeostatic overload?
When the animal fails to react to the threat or can’t deal with the stress
What are the two main hormones secreted by the adrenal gland during a stress response?
Adrenaline and glucocorticoid steroids
What does the activation of the HPA axis do?
Causes the release of glucocorticoid steroids from the adrenal cortex
What is the name of the glucocorticoid secreted in rodents, birds, lizards and amphibians?
What is the name of the glucocorticoid secreted in primates, large mammals, carnivores and fish?
What was found in ursin et al’s study on stress on military recruits?
Parachute jumps: testosterone was low immediately before and after the first jump- indicating a stress effect on the reproductive system
What was found in the study on the burrow system in rats?
Dominant males had lower corticosterone and higher testosterone levels
Dominant animals appear to have higher levels of 12-beta-HSD which inactivates glucocorticoid
What is different about dominant individuals in African wild dogs and dwarf mongooses?
Cortisol levels were higher in dominant individuals because they were involved in more aggressive encounters