Bridges, J. P., Mocarski, E. C., Reamer, L. A. et al. 2013. Weight management in captive chimpanzees (Pan troglodytes) using a modified feeding device. American Journal of Primatology 75(S1), 51. (36th Meeting of the American Society of Primatologists Scientific Program, Abstract #68)

Obesity, a common concern in captive chimpanzee populations, may lead to the development of various diseases and increase anesthetic risks. The aim of this study was to modify the current biscuit feeding devices and to utilize them in a way that provided enrichment while addressing weight management. The large food openings of the current feeding devices were adjusted by adding a polyethylene panel with smaller, various-sized holes designed to increase the time and effort required to obtain biscuits. The feeding devices were moved to different heights on the cage, requiring the chimpanzees to climb, and support their own weight to obtain biscuits. Total feeding time was recorded for seven groups of socially-housed chimpanzees (N=47) during 16 biscuit feedings: eight using the original feeding device and eight using the modified feeding device. Weights were documented from 30 chimpanzees (18 overweight and 12 normal weight) before and one to eight months after modification of the feeding devices. The amount of time spent obtaining biscuits significantly increased with the modified feeding device (t=-4.242, df=6, p=0.005). Additionally, overweight individuals weighed significantly less after implementation of the modified feeding device (t= 3.645, df=17, p=0.002), while the "normal weight" chimpanzees showed no significant weight loss (t=.503, df=11, p=.625). Simple modifications to existing feeding devices seem to be an effective method for facilitating weight loss and increasing feeding times in captive chimpanzees.