The Battle Within: Behavioural and Physiological Stress in Asian Elephants in a Human-Dominated Landscape in the Western Ghats, S. India

Introduction: What conservation problem or question does your study address?
Increasing habitat loss and fragmentation over the last century has led to persistent conflict between elephants and humans, and this may have had significant, yet uninvestigated, effects on the ecology, behaviour and physiology of elephants. In this study, we investigate the influence of anthropogenic landscapes, behavioural interactions with people and intraspecific social interactions on behavioural and physiological stress in an Asian elephant population

Methods: What were the main research methods you used?
The objectives of the study were to examine variation in behavioural and physiological stress across individual elephants of different age-sex categories and in different social associations in a plantation-rainforest landscape matrix. Accordingly, behavioural observations were carried out on 71 identified individuals in five different herds, using instantaneous group scans and focal animal sampling, to monitor visible measures of stress as well as behavioural interactions with conspecific individuals and with people. Fresh dung samples were then collected from these individuals at appropriate time points to measure their glucocorticoid content and to correlate these levels with their corresponding behavioural profiles. Behavioural and physiological stress was also measured in individuals occupying peripheral, relatively similar, but undisturbed, habitats.

Results: What are your most important results?
Our analyses indicate that levels of behavioural and physiological stress were most elevated in situations wherein individual elephants interacted agonistically with humans, for example, during drives or chases, than during their regular use of anthropogenic habitats. There were also no significant differences in stress levels across individuals of different age-sex categories and across herds in anthropogenic and peripheral, more natural, habitats.

Discussion: What are your important discussion points and what is the relevance of your results to conservation (if any)?
Our study elephant herds appeared to be adapted to their anthropogenic habitats, with persistently elevated levels of human interactions, and did not experience higher stress than did herds in peripheral, undisturbed habitats. The immediate stress that was generated in certain individuals and herds during agonistic interactions with people should, however, be taken into account when formulating management and conservation strategies for such herds.