Abstract # 202:

Scheduled for Monday, September 21, 2009 10:45 AM-10:55 AM: Session 20 (Del Mar Room) Oral Presentation


S. Rosenbaum1 and T. S. Stoinski2,3
1UCLA Department of Anthropology, 341 Haines Hall, Los Angeles, CA 90095, USA, 2Dian Fossey Gorilla Fund International, 3Zoo Atlanta

In the last 12 years, the mean number of subadult and adult male gorillas in the research groups monitored at Karisoke Research Center, Rwanda, has increased from three to nine. Recent work indicates that this significant change in demographics correlates with decreased monopolization of copulations by dominant males. Given the potential decrease in paternity confidence that may arise from the increased number of breeding-age males, a reexamination of the relationships between adult male and immature gorillas is in order. This study examines variation in male/immature interactions between 27 subadult and adult males (ages 8+ years) and 46 immatures (ages 0-6 years) across three groups of habituated mountain gorillas in Parc des Volcans, Rwanda, from August 2003 to December 2004 [N=508 hours of data]. Focal follows were conducted on all adult males. Both proximity and all-occurrence data of specific interactions were recorded, including aggressive and affiliative interactions. Results indicate that, similar to Stewart (2001), immatures tend to group around the dominant male. However, individual immatures deviate from this pattern, choosing to spend more time with specific non-dominant males. Additionally, subgrouping of infants is observed within larger groups, centered around non-dominant males. Support provided by the Leakey Foundation. The authors acknowledge the support of DFGFI and ORTPN in conducting this study.