Social structure, activity budgets and spatial relationships of the British & Irish captive population of lion-tailed macaques (Macaca silenus)

Abstract

Less than 2500 mature lion-tailed macaques (Macaca silenus) are left in the wild in the Western Ghats, India. It is important to manage and sustain the captive populations to gain an insight into this species and how to manage the wild fragmented populations.

The European captive population suffers from high infant mortality, large birth intervals and a low reproductive success amongst females. Thus the aim of this study was to assess possible causes of these three factors by investigating the social structure, activity budgets and spatial relationships in the captive British and Irish population of lion-tailed macaques. Observations were carried out at all zoos housing this species in the U.K. and Ireland.

Observations were made over 12 days per zoo at 09:00h, 12:00h and 15:00h. The average distance between individuals within a group was determined using Animal Tracker® computer software. Activity budgets were constructed for each zoo. Enclosure size, enclosure complexity, feeding regimes and visitor numbers were investigated to determine any influence on spatial separation distances and activity budgets. The social structure varied between groups due to age, sex and number of individuals and the facilities surrounding each of the groups. The degree of relatedness between females, as well as the size of enclosure, appeared to influence the spatial separation distances between individuals, although not significantly. The activity budgets varied between zoos, with autogrooming and foraging showing significant differences throughout all sampling periods. Significant differences in behaviour were also found between adult and juvenile lion-tailed macaques and in relation to time of day.

Visitor numbers and feeding regimes appeared to have no effect on the macaques' behaviour. However, enclosure size and enclosure complexity did appear to influence behaviour. In conclusion, this study of captive lion-tailed macaques gives an insight into how wild fragmented populations may be influenced by a reduced and isolated habitat. This study will also provide information regarding the welfare of captive lion-tailed macaques.