Abstract # 118:

Scheduled for Sunday, September 20, 2009 04:10 PM-04:30 PM: Session 11 (Mission Bay Ballroom AB) Symposium


SEX-SPECIFIC STRATEGIES DURING SIMULATED INTERGROUP ENCOUNTERS IN GREY-CHEEKED MANGABEYS (CERCOCEBUS ALBIGENA) IN KIBALE NATIONAL PARK, UGANDA

M. Brown1,2
1Columbia University, Department of Ecology, Evolution, and Environmental Biology, 1014B Schermerherhorn Ext, MC 5557, 1200 Amsterdam Ave, New York, NY 10027, USA, 2New York Consortium in Evolutionary Primatology
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Aggressive interactions among primate social groups function as a means of defending access to resources that limit individual reproductive success and are physically defendable. As a result of differing sets of constraints, male and female group-mates may simultaneously defend different types of resources. Due to their frugivorous diet, female philopatry, and estrus swellings, grey-cheeked mangabeys are expected to show food defense by both sexes and mate defense by males. I simulated intergroup encounters through playback experiments [n=67 trials] on six neighboring groups of mangabeys in Kibale National Park over 14 months. Male responses to playbacks were significantly affected by the focal group’s distance from its home range center and its size relative to the simulated neighboring group, but not by the presence of females with estrus swellings, the presence of infants, or the feeding value of the playback site [Linear regression, F(6,60)=3.59, p=0.0042, R2=0.264]. Female responses were significantly affected by the presence of infants, the feeding value of the playback site, the degree of intrusion by the simulated caller, and the size of the focal group relative to the simulated neighbor [Linear regression, F(5,61)=5.81, p=0.0002, R2=0.323]. These results indicate that mangabey responses to neighboring groups are considerably more complex than previously anticipated and are influenced by factors not addressed in older models of intergroup competition.