Abstract # 2671 Poster # 167:

Scheduled for Sunday, September 20, 2009 06:30 PM-09:00 PM: Session 14 (Mission Bay Ballroom CDE) Poster Presentation


VARIATIONS IN ANTI-PREDATOR STRATEGIES BETWEEN RING-TAILED LEMURS (LEMUR CATTA) LIVING IN TWO DIFFERENT FOREST TYPES AT BERENTY RESERVE, MADAGASCAR.

N. Ellwanger1 and L. Gould2
1Miramar College, 10440 Black Mountain Rd., San Diego, CA 92116, USA, 2University of Victoria, Canada
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Open habitats present increased predation risk because of differences in canopy cover, travel routes, and predator types when compared to gallery forests. This study examines the effect of habitat structure on anti-predator and predator sensitive foraging strategies of the ring-tailed lemur (Lemur catta) in Berenty Reserve, Madagascar. Data on vigilance, space usage, and foraging were collected over two months on two separate groups of ring-tailed lemurs (Lemur catta) living in distinctly different habitats: the xerophytic spiny forest is characterized by a small, non-continuous canopy whereas the riverine gallery forest is composed of large fruiting tree and continuous canopy. Mann-Whitney U Tests showed that individuals living in the sub-desert forest were significantly more vigilant [0.98 vs 0.27/hr, U=0, p<0.005, n=13], especially while sitting [2.8 vs 1.3/hr, U=2, p<0.01, n=13] and locomoting [4.6 vs .63/hr, U=0, p<0.005, n=13]. The two groups displayed no significant differences in social spacing or vertical level use while vigilant or feeding. Because of a lack of canopy connectivity, individuals living in the spiny forest most likely utilized terrestrial travel routes more often, exposing them to village dogs, a lethal potential predator. I suggest the group living in the spiny forest offsets the risks posed by the forest structure by increasing the rate of quick vigilance behaviors. However, predation risk was not strong enough to cause modifications in vital behaviors such as foraging.