Prevalence of stereotypies and its possible causes among captive Asian elephants (Elephas maximus) in Tamil Nadu, India

摘要

Animals in captivity are often confined in small barren enclosures, preventing adequate exercise, and socialization with conspecifics. Captivity is also known for depriving young individuals' association with maternal "relatives by weaning away from their mothers' earlier than what their peers experience in free-living populations. Such husbandry practices often lead to various welfare problems among captive animals. In India, Asian elephants are managed in captivity under various systems, for various purposes. To understand the effect of husbandry practices on the welfare of elephants, this study first time from a range country examined the prevalence of stereotypies and its possible causes among 144 captive Asian elephants managed under three captive systems Private, Hindu Temple and Forest Department in southern India. Occurrence of stereotypies and its possible influences by factors like age, sex, housing type and its size, duration of chaining and access to conspecific socialization were obtained by direct observations on each elephant and from registers maintained at each facility. Among the systems, the number of elephants with stereotypies was the highest in temple system (49%) followed by private (25%) and the lowest in the forest department (7%). None of the elephants that born in or brought from the wild and managed only at the timber camps was stereotyped. But those transferred from the timber camps to the temple, private and zoo and from the zoo to the timber camps showed stereotypies. Consistent with the prevalence of stereotypies among the three systems, number of elephants managed only at the indoor enclosure and duration of chaining were the highest in temple followed by private and the least in forest department system. The proportion of elephants displaying stereotypies and the proportion of time spent on stereotypies decreased significantly with age, indicating a greater vulnerability of young individuals to stereotypies. Further, logistic regression on prevalence of stereotypies with demographic and welfare parameters revealed that stereotypies decreased significantly with age and free access to con specific association until juvenile stage, indicating again the juveniles without conspecific association are more susceptible to develop stereotypies. Multiple regression on extent of stereotypies and various daily routines revealed that the extent increased significantly with daily rituals, resting, and marginally with feeding implying that prolonged daily rituals and resting promote its extent. It is argued that deprivation of association with maternal relatives and isolation from conspecifics result in the appearance of stereotypies among elephants in captivity, with younger individuals being more susceptible, perhaps the most active phase of their life being confined by chaining. (C) 2015 Elsevier B.V. All rights reserved.