Genetic structure of two populations of Alouatta caraya in continuous and fragmented habitats.

KOWALEWSKI M, OKLANDER L.

San Antonio, TX, USA.

Congreso; 29th Meeting of the American Society of Primatologists.; 2006

American Society of Primatologists

Demographic factors such as group size, group density, and male and female dispersal patterns can significantly affect the genetic structure of a primate population. In addition, habitat fragmentation may isolate populations and limit dispersal opportunities. We studied 7 groups of black and gold howlers inhabiting continuous forest (CF) on Isla Brasilera (27º 20' S, 58º 40' W) and 10 groups of black and gold howlers inhabiting a fragmented forest (FF) in Corrientes (27º 30’ S, 58º 41’ W) in northern Argentina. On the island, several groups have overlapping ranges whereas in FF each group was restricted to a forest fragment. We analyzed the genetic variability of these groups using seven polymorphic microsatellites: 3 for A. caraya (AC14, AC17, AC45), and 4 described for Homo sapiens (TGMS1, TGMS2, D5S117, D8S165). Our results indicate that neither population deviated from H-W equilibrium. However, Fst (inbreeding coefficient) values between-groups in the FF were consistent with a recent genetic differentiation between groups (Analysis of Molecular Variance: Fst=0.08805, p=0.000). In contrast Fst values between-groups in the CF showed no differentiation between groups (AMOVA: Fst 0.00771, p>0.05). These results suggest that habitat fragmentation may serve to decrease the ability of howlers to disperse between groups. Isolation can lead to inbreeding depression unless gene flow is restored by developing of biological corridors.