Abstract # 117:

Scheduled for Sunday, September 20, 2009 03:50 PM-04:10 PM: Session 11 (Mission Bay Ballroom AB) Symposium


RUN FOR COVER: NEOTROPICAL PRIMATES ALTER THEIR HABITAT UTILIZATION PATTERNS IN RESPONSE TO PERCEIVED PRESENCE OF HARPY EAGLES (HARPIA HARPYJA)

O. J. Neal and M. A. Norconk
Kent State University, 226 Lowry Hall, Department of Anthropology, Kent, OH 44242, USA
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The concept of predator-sensitive foraging asserts that primates evaluate their surroundings and make foraging decisions that reduce risk. Therefore, it is expected that they also evaluate the relative safety of habitats when encountering predators in order to make appropriate avoidance or evasion decisions. Over a three month period in 2008, playback experiments were conducted on all eight sympatric primate species in Suriname, South America. These experiments involved broadcasts of vocalizations of two neotropical avian species: non-predatory screaming pihas (Lipaugus vociferans; control group) and predatory harpy eagles (Harpia harpyja; experimental group). Overhead canopy density was measured in one minute intervals throughout each experiment with a spherical forest densiometer (Model A: Forest Densiometers; Bartlesville, OK), which indicated the amount of light allowed to penetrate canopy foliage, providing an estimate of the percentage of canopy obstruction. Paired t-tests were conducted to test whether canopy density was significantly different between control and experimental groups. Although the total mean percentage of canopy cover was relatively high [83.33%; n=176], there was a significant increase in percentage of canopy obstruction during and after H. harpyja vocalization playback across all species [t(28)=2.36, p=0.026; two-tailed]. These results suggest that neotropical primates evaluate the relative safety of their surroundings and seek refuge in less risky habitats in response to the perceived presence of predators.