Abstract # 2733 Event # 106:

Scheduled for Sunday, September 20, 2009 10:45 AM-10:55 AM: Session 9 (Del Mar Room) Oral Presentation


SOCIAL MONOGAMY: PROXIMITY MAINTENANCE AND FORAGING PATTERNS IN THE WILD ARGENTINEAN OWL MONKEY (AOTUS AZARAI AZARAI)

M. L. Gustison1, C. T. Snowdon1 and E. Fernandez-Duque2
1University of Wisconsin-Madison, Department of Zoology, Madison, WI 53706, USA, 2Department of Anthropology, University of Pennsylvania, Philadelphia, PA, 19104, USA
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When attempting to explain the evolution of social monogamy, the paternal care hypothesis predicts that fathers maintain a close relationship with offspring. The food distribution hypothesis predicts that high-quality food resources are over-dispersed and scarce. To test these predictions, we collected data during 884 hours of contact on foraging trees [N=352], ranging locations [N=452] and behavioral interactions [88hs] from four owl monkey groups and two solitaries during July-August 2008 when food was less abundant. Infants were more responsible for maintaining proximity to their parents [Hinde’s index (mean ± SE), males: 27%±6%; mothers: 40%±6%], than juveniles [males: 2%±14%; mothers: 25%±6%]. Infants tended to have the males as nearest neighbors more frequently than their mothers [scans/focal: 3.9 vs 2.9, t(4)=1.86, p=0.14], but there was no difference for juveniles [scans/focal: 1.2 vs. 1.2]. While foraging, groups used 91% ± 5% of their territories, shared 7% of the trees with solitaries, and shared 2% with other groups. Compared to all of the foraging trees in the study area, shared trees were used more frequently for obtaining fruits [47% vs 67%, t(30)=2.53, p=0.02] and less frequently for leaves [16% vs 5%, t(50)=3.05, p=0.004]. These findings provide some preliminary evidence that proximity maintenance is a possible mechanism of paternal care and that high-quality foods are scarce but not over-dispersed.