Factors influencing stereotypic behaviours of animals rescued from Asian animal markets: A slow loris case study

- Slow lorises in rescue centres often exhibit stereotypic behaviours.
- We analysed possible causal extrinsic factors.
- Sex composition in cage and length of time at rescue centre were significant.
- Confiscated lorises should be housed in same-sex groups.

Illegal wildlife trade has devastating effects on wild populations in Southeast Asia, made evident from the rising numbers of threatened species found in rescue centres. The prevalence of slow lorises (Nycticebus spp.) in trade allows for the first time, a study of the response of wild-caught strepsirrhines to a captive environment following a period of non-existent welfare. Many animals confiscated from trade arrive at rescue centres with mental and physical defects and regularly perform stereotypic behaviours. Our study assessed the prevalence of stereotypic behaviour in three species of Indonesian slow lorises (n = 90) at a Ciapus Primate Centre in Java, Indonesia. We surveyed all slow lorises present, three times a night, every night, over a four-week period and recorded every time a slow loris exhibited stereotypies. We described the stereotypic behaviours witnessed and attempted to predict the occurrence of this behaviour. 33% of animals observed exhibited at least one of three forms of stereotypy - pacing, rocking head, circling. We examined extrinsic and intrinsic factors including sex, species, length of time in captivity, cage size and group composition to highlight stereotypic predictors. A logistic regression analysis revealed that 21.9% of variability in the presence of stereotypies could be explained by sex composition and number of conspecifics sharing an enclosure. Through experimenting with different size and sex composition of groups and distance to neighbouring groups, occurrence of stereotypies may be reduced. Numerous other factors not tested for, including a genetic predisposition to coping with life in captivity, could be responsible for these behaviours. As stereotypies in zoo-living lorises are rare, the brutal conditions of the trade may also play a major role in their prevalence in this study.