Abstract # 2828 Event # 139:

Scheduled for Saturday, June 19, 2010 02:30 PM-02:40 PM: Session 25 (Medallion Ballroom B) Oral Presentation


DO GREY-CHEEKED MANGABEY (LOPHOCEBUS ALBIGENA) GROUPS IN KIBALE NATIONAL PARK, UGANDA, STILL AVOID THEIR NEIGHBORS WHEN THE POPULATION DENSITY INCREASES?

M. Brown1,2
1Columbia University, 1014 Schermerhorn Ext, MC5557, 1200 Amsterdam Ave, New York, NY 10027, USA, 2The New York Consortium in Evolutionary Primatology
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Long-distance calls are thought to function as an intergroup spacing mechanism. Early studies demonstrated that grey-cheeked mangabeys in Kibale National Park, Uganda, exhibited an extreme form of spacing; they moved away after hearing neighbors’ long-distance calls, regardless of location. In the current study, I documented a group density three times higher than seen in the original study population but it is unclear whether mangabey groups still avoid their neighbors. My team recorded long-distance calls [N=437] and center-of-mass locations during simultaneous follows of seven groups over 15 months at the Ngogo research station in Kibale National Park. Even at a high density, groups still tend to withdraw from, rather than approach, neighbors’ calls [Binomial Test: P<0.002], but they are more likely to approach when in the core than in the periphery of their own home range [Pearson: X2(1)=5.29, P=0.021]. A multiple logistic regression further indicates that the odds of approach increase when the listening group is large, the caller is in the periphery of its own range, food abundance is high, and the listening group was already moving towards the caller prior to the call [X2(9)=35.53, P<0.001]. Thus it appears that mangabeys avoid their neighbors regardless of population density, but that this response is weaker at high densities than at low densities and is contingent on a number of social, spatial, and ecological factors.