Coping is a behavioral response to aversive situations that induce physiological stress reactions. From an evolutionary perspective, aversive situations will likely result in reduced fitness if the animal fails to cope (Broom, 1991). The success of the coping behavior can be measured by its effectiveness in reducing physiological measures of stress or by its effectiveness in removing an aversive situation and thus restoring fitness.
Coping is an exciting concept in animal science and an individual's possible adaptive response strategies to stimuli, including the behavior plasticity topic.
If you are interested, explore the nine schemes created by Donald Broom and Kenneth Johnson (1993). I'll give you their introductions, so you have a starting point.
In the face of stimuli, an internal steady-state is maintained with ordinary basal responses. The state of being is very well.
Complete adaptation was achieved with a minor extraordinary response. Stimuli provoke adaptation. Fitness and performance may be briefly compromised, but wellness promptly returns.
Sometimes, animal response to stimuli over time is neither extraordinary nor adequate. For so long as the impingement continues, fitness and performance may be reduced, and minor stress and fairness ensue, but after that, wellness returns.
Stimuli elicit some minor extraordinary responses, but over time this is inadequate for complete adaptation. Both fitness and performance decrease for a while (fairness), after which wellness returns. Stress is present in schemes four and above.
An animal's extraordinary response over a long period achieves only incomplete adaptation. Although fitness remains relatively high, performance is reduced. The animal experiences overall fair-being.
To completely adapt, an animal sometimes must mount an extreme response. During adaptation and recovery periods, fitness and performance decline. The animal is only fair.
Despite some extraordinary responses to stimuli, complete adaptation is not achieved long term. Fitness and performance decline; the animal becomes ill.
In some cases, an extreme response does not result in complete adaptation, even long term, reducing the ill animal's fitness and performance.
An environmental stimulus may be so enormous and swift that the animal succumbs before it can respond.
References
Broom, D.M. (1991). Assessing welfare and suffering. Behav. Proc., 25: 117-123.
Broom, D.M., Johnson, K.G. (1993). Stress and Animal Welfare. Kluwer Academic Publishing: Amsterdam.