Improving the welfare of captive macaques (Macaca sp.) through the use of water as enrichment.

This review evaluates the use of water as a tool for enriching the environments of macaques (Macaca sp.) in captivity. Many macaque species are known to swim and forage in water in the wild, and in-situ reports suggest that access to water promotes activity and cultural behavior. Yet, there is a relative dearth of information on water enrichment, covering only a small number of macaque species in both laboratory and zoo settings. Previous studies in captivity report high levels of usage of water enrichment as well as further behavioral benefits, including increases in play, exploratory behavior, and tool use. Subsequently, there is a clear need for more research on the potential benefits of water enrichment for both macaques and other primate species, especially given that small water troughs and pools provide an inexpensive method for enriching nonhuman primate lives in captivity.

Two cases of mother-infant cannibalism in orangutans.

Observations of ape cannibalism have to this point been limited to chimpanzees (Pan troglodytes) where it is associated with infanticide and consumption by unrelated individuals (Watts and Mitani, Primates 41(4):357-365, 2000). Here we report for the first time observations of two unrelated female Sumatran orangutans (Pongo abelii) cannibalizing the remains of their infants on different occasion, a behavior never before reported in any ape species. The two orangutans were wild-born rehabilitated individuals, and had been reintroduced to an area hosting a largely unregulated primate tourism industry and experienced restricted ranging conditions. Though it is possible that this is a strategy to regain energy and nutrients or a result of individual history, comparative data suggest that this is an aberrant behavior which may be linked to environmental stressors within the area.