The 85th Annual Meeting of the American Association of Physical Anthropologists (2016)

A preliminary examination of genetic diversity in mantled howler monkeys (Alouatta palliata) in a fragmented forest in Costa Rica


1Department of Biology, Regis University, 2Department of Biology, Salt Lake Community College

April 16, 2016 , Atrium Ballroom A/B Add to calendar

Dispersal from one’s natal group reduces inbreeding. Habitat fragmentation may limit primates’ dispersal opportunities, however, which has implications for species survival. We examined the influence of fragmentation on genetic diversity in wild mantled howler monkeys (Alouatta palliata) at La Suerte, Costa Rica. The La Suerte region has seen increased fragmentation over the past decade as forest has been cleared for fruit plantations. We hypothesized that genetic diversity would be lowest in the forest edges compared to the interior because fragment boundaries restrict dispersal opportunities for edge groups. In summer 2014 we collected 41 fecal samples from the howler population. To examine polymorphism, we isolated DNA from these samples and used primersets to perform PCR amplifications of selected microsatellite loci. We overlaid these data with the locations of sample collections. Our initial results show that genetic diversity is highest at the edges of the forest and lowest in the interior. We also calculated inbreeding coefficients via fixation indices which suggest that this population may be outbred. This suggests that howler monkeys may be dispersing across open areas into neighboring fragments. These results may, however, be an artifact of our limited sample size. We therefore collected additional samples in summer 2015 allowing us to establish a firm baseline to monitor the relationship between changes in the landscape and population structure over time. The results we present here are the initial stage of what we anticipate will become a long-term project examining the influence of habitat fragmentation on dispersal and genetic diversity.