Abstract # 2614 Poster # 73:

Scheduled for Saturday, September 19, 2009 06:30 PM-09:00 PM: Session 5 (Mission Bay Ballroom CDE) Poster Presentation


A COMPARISON OF GESTURAL COMMUNICATION IN ZOO-LIVING CHIMPANZEES (PAN TROGLODYTES) AND GORILLAS (GORILLA GORILLA GORILLA)

L. W. Smith1,2
1CUNY Graduate Center, Department of Anthropology, 365 5th Avenue, New York, New York 10016, USA, 2New York Consortium in Evolutionary Primatology (NYCEP)
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Gestural signaling is fundamental to primate communication. Previous examinations of manual gestures and body postures in African apes have chiefly focused on subadults, thereby not taking into account possible age class variation. This project investigated gestural communication in terms of differences in function, flexibility, and audience effects in two African ape species. Data were collected on all available age classes of two chimpanzee groups [11 individuals at the St. Louis Zoo and 13 individuals at the Los Angeles Zoo], and two western lowland gorilla groups [two groups of 11 and 13 individuals at the Bronx Zoo]. Over 700 total hours of observational data were obtained via continuous video recording of social interactions. Both species used gestures flexibly in various social contexts, though gorillas had a larger gestural repertoire than chimpanzees. Gorillas under 10 years old produced the majority of gestures recorded, while chimpanzees above 10 years old produced the majority of gestures. All study groups used more tactile gestures than visual or auditory gestures. Across all groups and species, gestures were used more often when the recipient was attending to the signaler, especially when using visual gestures. Differences in the gestural repertoires of African apes may be related to environment, social dynamics, and positional behavior. Understanding these differences may help explain the evolution of gestural signaling.