Abstract # 88:

Scheduled for Friday, June 22, 2012 11:15 AM-11:30 AM: Session 11 (Magnolia) Oral Presentation


FORAGING AND TRAVEL PATTERNS OF WHITE-FACED SAKIS (PITHECIA PITHECIA) AT BROWNSBERG NATURE PARK, SURINAME: EVIDENCE FOR GOAL-DIRECTED FORAGING BEHAVIOR

A. Anzelc and M. A. Norconk
Kent State University, Department of Anthropology, Kent, OH 44242, USA
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     Many researchers have found that primates conserve energy by traveling linearly and quickly towards preferred resources using distance-minimizing travel paths (i.e., are goal-directed). White-faced sakis inhabit and defend small home ranges (25 ha) and ingest seeds (patchily distributed in space, but have a relatively long period of availability). Abundant food in a small space does not necessarily predict goal-directed foraging patterns, thus we studied the travel paths of a well-habituated group of sakis for seven weeks to assess linearity in travel to feeding trees, frequency of revisits to feeding trees, use of navigation “landmarks” and effects of home range boundaries on foraging routes. Routes were documented using compass readings; pedometer tracking and post-hoc GPS waypoints for start and stop points. Daily travel routes were generated using EasyCad v. 7 and compared to hypothetical straight-line routes. Directedness ratios (DR) were computed for all inter-tree combinations (n = 246), where DR of 1.0 (inter-resource straight-line distance/observed distance) is a straight line. The observed directedness ratio was 0.81 and 84% of angles were ? 90 degrees indicating forward progression and rare backtracking. DRs were significantly straighter when reusing trees than for first-time feeding (z = -2.1, p < 0.05) and were more erratic when approaching a home range border. Sakis use goal-directed travel often, but travel routes are also influenced by territorial monitoring and seeking new food sources.