Carey, M. C., West, A. M., Lozano, A. et al. 2012. Designing gum-based enrichment for captive patas monkeys (Erythrocebus patas). American Journal of Primatology 74(S1), 42. (35th Meeting of the American Society of Primatologists Scientific Program, Abstract #53)

In the wild, patas monkeys (Erythrocebus patas) consume Acacia spp. gum for 20% of their active time. While providing gum-based enrichment to other gummivorous primates is not a unique idea, there have been no reports of captive patas monkeys receiving gum enrichment. Gum is not required in the captive diet, but this form of enrichment may encourage naturalistic behaviors for a species noted to lack motivation with other devices. Gum feeders were constructed by drilling holes into Manzanita wood, filling them with prepared gum arabic, and plugging the holes with crystallized chunks of gum. This was to simulate the method of feeding on globs of Acacia gum observed in the wild. The colony of patas (n=34) were split equally into two treatment groups (gum-enrichment first, plain log feeder first) and treatments were provided in two-week phases until all forms of enrichment were received. Observations were recorded for a total of 90 min per individual over six weeks (including baseline observations) and frequency of exploratory and foraging behaviors were scored to determine the effect of gum enrichment on these behaviors. Results indicate that there is an increase in foraging and exploration behaviors when gum-feeders are provided as opposed to standard-baseline enrichment (ANOVA, α=0.05, p<0.0001). Gum-log feeders appear to be a relatively easy way to encourage natural foraging and exploratory behavior in captive patas monkeys.