Monitoring stress in captive and free-ranging African wild dogs (Lycaon pictus) using faecal glucocorticoid metabolites

Abstract

An understanding of stress physiology is important for species management because high levels of stress can hamper reproduction and affect an individual's ability to cope with threats to their survival, such as disease and human-wildlife conflict. A commonly used indicator of stress, faecal concentrations of cortisol metabolites (FCM), can be used to assess the impact of social, biological and environmental factors. Measurements of FCM are particularly valuable for endangered species that are logistically challenging to study and where non-invasive techniques are preferred. As the second most endangered canid in Africa, the African wild dog (Lycaon pictus) has been the focus of considerable conservation research, yet there is still little understanding of factors associated with stress, in either captive or free-ranging populations. The present study therefore aimed to determine whether stress levels differ between captive and free-ranging populations, and to detect social, biological and environmental factors that are stressful in these populations. Faecal samples were collected from 20 captive and 62 free-ranging animals. Within free-ranging populations, the sexes differed significantly, but there was no effect of social status, age or breeding period for either sex.Captive females had higher FCM concentrations than free-ranging females. In captive populations, FCM concentrations differed among zoos and with reproductive status in females, but were not related to age class or group-housing structure. In conclusion, FCM is a useful indicator of stress and should be considered an integrative aspect of management, for both in-situ and ex-situ African wild dog populations.

Faecal glucocorticoid metabolite concentrations and their alteration post‐defaecation in African wild dogs Lycaon pictus from South Africa

“…Although hormone monitoring is widely used to examine responses to stressors in captive and free-ranging African wild dogs (Creel 2005, Vlamings 2011, van der Weyde et al 2016, potential differences in faecal glucocorticoid metabolite (fGCM) concentrations post-defaecation have not been investigated. As a result, previous studies that aimed to identify perceived stressor complexes in African wild dogs have, by necessity, relied on intense observation of individuals for the collection of faecal samples as soon as possible post-defaecation.…”

Appeasing Pheromones for the Management of Stress and Aggression during Conservation of Wild Canids: Could the Solution Be Right under Our Nose?

“…Despite this, there is limited monitoring of the parameters of physiological stress described in the literature during the conservation management of wild canids, even though behavioural distress is commonly reported [20,22,81]. Interestingly, captive African wild dogs show significantly higher stress-related fGCMs than their free-living counterparts [82]. Similarly, permanent and temporary captivity results in similar fGCM concentrations, both of which are higher than in free-living African wild dogs, although this study relied on a single defecated sample, and did not report the length of time the animals had been kept in temporary captivity prior to the sample's collection [60].…”

“…[56,62,84,85]. The level of aggression displayed by dominant animals is directly related to the attainment and maintenance of dominance hierarchies, with alpha animals having elevated glucocorticoids year-round compared to their subordinate pack mates [82,86]. Furthermore, dominant animals are more aggressive and fight more than their subordinates during periods of mating and, as such, the breeding season is a suboptimal time for translocation and artificial pack formation [56].…”

Effect of food limitation and reproductive activity on fecal glucocorticoid metabolite levels in banded mongooses

“…Our ancillary experimental approach, suppressing reproductive activity in and providing constant daily food supply to a group of captive banded mongoose, allowed us to partial out effects of different stressors and provided context (relative effect sizes and timing of glucocorticoid production) for understanding the revealed glucocorticoid patterns. Comparisons between the free-living and captive mongoose fGCMs should be interpreted with caution as glucocorticoid responses to stressors may differ among captive and free-living individuals [40][41][42].…”