Abstract # 2719 Event # 114:

Scheduled for Sunday, September 20, 2009 02:50 PM-03:10 PM: Session 11 (Mission Bay Ballroom AB) Symposium


PREDATOR MODELS AND A MOBILE FEEDING PLATFORM USED TO INVESTIGATE PREDATOR-SENSITIVE FORAGING IN WEDGE-CAPPED CAPUCHIN MONKEYS (CEBUS OLIVACEUS).

L. E. Miller
MiraCosta College, Dept. of Anthropology, Oceanside, CA 92056, USA
line
     

Predator-sensitive foraging represents the strategies that animals employ to balance the need to eat against the need to avoid being eaten. These strategies may be complex responses to both predation risk (i.e., the odds of encountering a predator) and individual vulnerability (e.g., group size or body size). Teasing apart the influence of these variables is challenging through naturalistic observations; however, experimentation can control certain variables while manipulating others. This study took place at the Hato Pinero Biological Station in central Venezuela, with a population of wild wedge-capped capuchin monkeys (Cebus olivaceus). The impact of risk was assessed through manipulation of a mobile feeding platform and model snakes. The impact of vulnerability was assessed via group size. The key dependent variable was latency to approach the platform. The prediction that increased risk would lead to increased latency to feed was clearly supported by the data [low risk vs. medium risk trials, n=37, matched pairs t=4.34, p<0.0001; medium risk vs. high risk trials, n=27, matched pairs t=5.39, p<0.0001]. However, the prediction that increased vulnerability would lead to increased latency to feed found only moderate support and only at the highest risk condition [unmatched t=1.47, p=0.78]. Although many studies have suggested that predation impacts foraging decisions, the data are largely circumstantial. Experimental protocol offers many challenges, but has the potential to offer clearer analyses of behavioral responses.