Abstract # 105:

Scheduled for Friday, June 18, 2010 07:00 PM-09:00 PM: Session 18 (Medallion Ballroom C/D/E/F) Poster Presentation


C. L. Thompson1, M. A. Norconk1, A. Anzelc1, T. Gregory1, D. Hurst3 and N. Robl2
1Kent State University, Department of Anthropology, Kent, OH 44242, USA, 2School of Veterinary Medicine, University of Wisconsin, Madison, 3Department of Anthropology, Indiana University

Our knowledge of white-faced saki population dynamics is currently limited. Observational studies of white-faced sakis have been conducted either on an island or in habitat fragments, confounding attempts to understand white-faced saki grouping patterns. We present data on population and group dynamics of white-faced sakis in a free-ranging environment. Three habituated groups are present at Brownsberg Nature Park: one has been observed since 2003, the second since 2005, and the third since 2008. Partial group compositions are known for 3 additional unhabituated groups. Group size ranged from 2 to 7 with a one to two breeding females and males per group. We documented 7 births; two of which died as infants [29%] and three died as juveniles [43%]. Four adult/subadult disappearances of have been recorded, of which at least two were established breeding group members, including an alpha male. We observed one instance of group inheritance by a younger male and subsequent immigration of a nulliparous female. Two instances of lone ranging (possibly floater) males at the edge of group’s home range have been recorded, and one lone, possibly dispersing, female in the middle of an established group’s range. Given these data, white-faced sakis best fit an age-graded male social organization, although considerable variation exists in social organization and mating system, ranging from one-male, one-female units to small multi-male, multi-female groups.