Abstract # 54:

Scheduled for Thursday, June 21, 2007 05:00 PM-07:00 PM: Session 7 (South Main Hall) Poster Presentation

Sexual Behavior in Western Lowland Gorillas

T. S. Stoinski1,2, A. Legg1, E. Price1 and R. Antworth1
1Zoo Atlanta, 800 Cherokee Ave. SE, Atlanta, GA 30315-1440, USA, 2Dian Fossey Gorilla Fund International
     Studies of wild mountain gorillas report that female gorillas compete for social but not sexual access to the dominant silverback. The current study focused on sexual behaviors in a newly-formed group of western lowland gorillas (Gorilla gorilla gorilla) housed at Zoo Atlanta. The group consisted of one silverback and three adult females and one subadult female, all of whom were cycling at the beginning of the study. Data were collected using focal animal sampling (N=151 hours). All females were observed to solicit and copulate with the silverback during pregnancy and after parturition, although there was considerable individual variation in the behavior. Chi-squared analyses [a=0.05] revealed the frequency of co-solicitation or co-copulations (e.g. two or more females soliciting/copulating on the same day) did not deviate from chance when all females were considered together. However, at the individual level, two adult females showed overlapping sexual behaviors significantly more frequently than expected. The results provide limited evidence that females may compete for sexual access to males. Additionally, the presence of active solicitation during pregnancy and lactation emphasizes the importance of female counterstrategies to infanticide in this species.