The 84th Annual Meeting of the American Association of Physical Anthropologists (2015)

Ring-tailed lemurs (Lemur catta) in small forest fragments: Which variables are the best predictors of population viability and juvenile recruitment?


1Department of Anthropology, University of Victoria, 2Department of Mathematics and Statistics, University of Victoria, 3Department of Biology, University of Victoria

March 28, 2015 , Gateway Ballroom 2/3/4/5 Add to calendar

Primates worldwide are increasingly restricted to fragmented habitats surrounded by anthropogenic landscapes (grasslands, villages, crops). Variables important to primate population viability in fragments include dietary and behavioral plasticity, flexible home range size, and capacity to utilize matrix habitat surrounding the fragment. Due to massive deforestation, forest cover in south-central Madagascar has been reduced to small fragments dotting the landscape. Populations of Lemur catta persist in some of these fragments. Our aim was to evaluate potential for L. catta population viability in 9 fragments of varying sizes (2-46ha) in this region using comparative ecological measures. We used log linear models to examine effects of fragment size, within-fragment food tree density, and number of food resources in surrounding matrices on L. catta population size and juvenile recruitment. We found significant associations between total population size and fragment size, food tree density along transects, and number of matrix resources within 200 meters of fragment edges. Juvenile recruitment was positively correlated with fragment size and within-fragment food tree density, but not matrix resources. While these results are useful for predicting population viability, two additional variables: 1) degree of human disturbance within fragments, and 2) potential for male dispersal to other L. catta populations, play an equally important role in the likelihood of population persistence of ring-tailed lemurs in such fragmented habitat. While 7/9 fragments in our study were reasonably well protected from human disturbance, only 3 offered realistic potential for male dispersal, thus the long-term survival of most of these populations is highly uncertain.