The comparative biology of environmental stress: behavioural endocrinology and variation in ability to cope with novel, changing environments

Coping with perturbations of the environment such as severe storms and other climatic extremes, habitat degradation, changes in predator numbers, invasive species and social disruption is one of the most essential physiological and behavioural processes. The palaeontological record shows that organisms have had to cope with environmental perturbations throughout the history of life on Earth. These ancient processes show highly conserved mechanisms, but also great flexibility in responses to social and physical environment challenges. Adrenocortical responses to perturbations can trigger a coping response called the emergency life history stage (EHLS). However, if the adaptive value of the ELHS declines because of trade-offs with other life history stages such as breeding, then the adrenocortical response to acute perturbations (stress) can be modulated. Mechanisms involve allostasis and reactive scope with three foci of regulation: hormone secretion, transport and response. It is now well known that modulation of the adrenocortical responses to perturbations occur through gene-environment interactions during development and throughout the life cycle. These modulations involve individual differences in gender, age, experience and condition as well as latitudinal, altitudinal and hemispheric variations. Dramatic consequences of human-induced rapid environmental change such as increasing frequency and intensity of environmental perturbations will likely have implications for continued adaptation to extreme events. Note that modulation of the stress response also involves three major processes: modulation of robustness (i.e. become more resistant to acute stress); modulation of responsiveness (i.e. modulate the actual response to stress for more flexibility); and modulation of resilience (i.e. how quickly and completely the recovery is after the perturbation has passed). Mechanisms underlying these modulations remain largely unexplored. (c) 2013 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.