Reponses to food, novelty and activity in captive Asian elephants (Elephas maximus)

Abstract

Animals respond to external environmental stimuli which alters their physiology and behaviour and enables individuals to navigate their environments. This can mean i.e. seeking shade at the hottest parts of the day in response to physiological skin responses or refusing to consume a novel food after investigation, to reduce the possibility of toxicosis. In this thesis I investigate the physiological and behavioural responses of Asian elephants (Elephas maximus) using a captive population which are owned by an eco-tourism facility in southern Nepal. Utilising captive Asian elephants as a study system allows for rigorous data collection using both observational methods and experimental design, which would be challenging with wild individuals. Furthermore, the mahout system, where elephants have 1-2 designated carers who enable a barrier-free approach, allows for a safe and controlled environment in which to assess elephant physiology and behaviour.

Through behaviour-focused choice tests and presentation experiments, I assessed elephant responses to food items using different sensory modalities. I found that in choice tests elephants did not make consistent choices for specific familiar food items. In further presentation experiments I found that senses did not affect elephant food-based behaviour as predicted, possibly due to the distances used in the study. However, when investigating novel and familiar foods, elephants showed cautionary behaviours for novel foods indicating possible neophobic tendencies for this species in a foraging context. These findings prompted further study of elephant food preferences and responses to food novelty, removing sensory limitations which had shown no effect on elephant behaviour. I found no strong justification for food preferences, regarding individual food items used in the experiment at either a population or individual level. However as with previous work, elephant behavioural responses did differ depending on whether food items initially encountered were novel or familiar, but these differences changed through time.

The physiological element of this thesis aimed to investigate captive elephant responses to temperature dependent on exercise type. This study was undertaken at the request of the eco-tourism facility to deduce possible negative effects of a highly contended elephant polo competition which occurred on an ad-hoc basis at the site in the winter. I compared elephant skin temperature change in individuals competing in the polo tournament with those continuing with eco-tourism activities e.g. trekking with tourists. Although we found no differences in elephant skin temperature between activities, we did find differences in the skin temperature of distal body regions when compared to core body temperature. Regions more highly impacted were either heat loss mechanisms for elephants (ear pinnae) or areas more highly impacted by equipment utilised in the activity.

Overall, my results provide a more thorough comprehension of elephant physiology and behaviour in different contexts. They provide a basis for understanding which food items may be used to motivate elephants during training and of elephant responses to novelty in a foraging context. Physiological results convey the importance of including temperature as a metric for welfare and to inform on how elephants are managed in captivity, especially within the tourism sector.