1Department of Anthropology, The Ohio State University, 2CARPO Program, WWF-Gabon, Libreville, Gabon
Saturday All day, Park Concourse
Several factors influence the ranging of primate populations including group size, predation pressure, and the spatio-temporal availability of foods. Cercocebus torquatus, the red-capped mangabey, in Sette Cama, Gabon, has a large group size (~70 individuals) but a smaller home range (250 hectares) than other mangabeys of similar group sizes. We hypothesized that C. torquatus would show minimal seasonal variation in its habitat use because of the nature of their habitat. Group members should also exhibit a high degree of vertical group spread. GIS analysis is a useful tool for studying primate ranging patterns as it offers a means to compare movements to multiple variables. A total of 635 GPS points were collected during 2008-2009 and analyzed using ArcGIS 10. The vertical distribution of the group members in the forest was also recorded. C. torquatus movements were spatially correlated (Moran’s index: 0.596, p=<0.001) indicating that they repeatedly return to the same areas within their habitat. The ranging patterns of the group were only slightly related to the seasonality of resources (ordinary least squares, wet season: F=.664, p=0.05; dry season: F=0.019, p=0.05) which differs from other populations of C. torquatus. The group had a mean diversity index of vertical distribution of 0.47. We suggest that C. torquatus maintains its large population in a small home range in part by intensively using its habitat and concurrently occupying different levels of the forest. The importance of subgrouping for the maintenance of this large population is also discussed.