Rating Methodology, Personality Axes, and Behavioral Plasticity: A Case Study in African Lions

Animal personality refers to individual differences in behavior that are consistent across time and across contexts. As it plays an ecological and evolutionary role for many animals by affecting fitness, it is likely to play a role in how both species and individuals fare in captivity. Assessment of animal personality by caretaker ratings has been […]

The physiological significance of the circadian dynamics of the HPA axis: Interplay between circadian rhythms, allostasis and stress resilience

Circadian time-keeping mechanisms preserve homeostasis by synchronizing internal physiology with predictable variations in the environment and temporally organize the activation of physiological signaling mechanisms to promote survival and optimize the allocation of energetic resources. In this paper, we highlight the importance of the robust circadian dynamics of allostatic mediators, with a focus on the hypothalamic-pituitary-adrenal […]

Non-invasive measurement of glucocorticoids: Advances and problems

Glucocorticoids (GCs; i.e. cortisol/corticosterone) are a central component of the stress response and thus their measurement is frequently used to evaluate the impact of stressful situations. Their metabolites from faeces of various animal species are more and more taken as a non-invasive aid to assess GC release and thus adrenocortical activity. The current literature review […]

Coping style and cortisol levels in infancy predict hair cortisol following new group formation in captive rhesus macaques (Macaca mulatta)

Social instability in primate groups has been used as a model to understand how social stress affects human populations. While it is well established that individual cercopithecines have different temperaments or personalities, little is known about how temperament mediates the experience of social instability in large, naturalistic groups. Here, we report findings from a study […]

Preliminary data showing potential for salivary C-reactive protein as an indicator of welfare in western lowland gorillas (Gorilla gorilla gorilla)

C-reactive protein (CRP) is an acute phase protein often used as a biomarker for inflammation related to acute trauma or chronic illness. Animal studies showing elevations in CRP following events such as road transport and moving to new housing suggest that CRP fluctuations may indicate how behavioral stress affects animal welfare. As part of a […]

Corticosterone in feathers is a long-term, integrated measure of avian stress physiology

1. Stress has pervasive consequences for the well-being of animals. Currently, understanding how individuals cope with stressors is typically accomplished via short-term quantification of blood glucocorticoids released after activation of the hypothalamic–pituitary–adrenal (HPA) axis. 2. We investigated whether the amount of corticosterone (CORT) deposited in growing feathers provides a long-term, integrated measure of HPA activity […]

Dominance, aggression, and glucocorticoid levels in social carnivores

In social animals, reproductive success is often related to social dominance. In cooperatively breeding birds and mammals, reproductive rates are usually lower for social subordinates than for dominants, and it is common for reproduction in subordinates to be completely suppressed. Early research with captive animals showed that losing fights can increase glucocorticoid (GC) secretion, a […]

Stress impairs spatial but not early stimulus–response learning

Recent evidence indicates that stress modulates multiple memory systems, favoring caudate nucleus based stimulus–response learning at the expense of hippocampus-based spatial learning. Whether this is due to a facilitating effect of stress on stimulus–response learning, an impairing effect on spatial learning, or both, is not known. To answer this question, mice were either subjected to […]

In search of relationships between the acute adrenocortical response and fitness

The assumption that the acute response to stress is adaptive is pervasive in the literature, but there is little direct evidence regarding potential positive fitness consequences of an acute stress response. If acute glucocorticoid (GC) elevation increases lifetime reproductive success (fitness), in what contexts does this occur, and through what combination of effects on annual […]

Stress: An inevitable component of animal translocation

As the number and diversity of animal species meriting conservation intervention increases, improving the success of translocation efforts is vital and understanding the role of physiological stress in translocation failure is essential. Though the short-term acute stress response is critical for survival in the wild, chronic stress results in pathology and occurs when the physiological […]