Patterns of genetic diversity in populations of two bat species (Sturnira ludovici and Artibeus toltecus) in Cusuco National Park, Honduras

Habitat loss, disturbance and fragmentation are thought to be major threats to many species, particularly those in habitats that are already rare. In this study, we examined whether habitat disturbance, primarily due to the cultivation of coffee, has had a major impact on populations of two species of bats in a Honduran cloud forest, using genetic diversity as a measure of population health. Bats were selected as the study species because they play a major role in seed dispersal within the tropics. I compared the genetic diversity of two frugivorous bat species, Sturnira ludovici and Artibeus toltecus, between two localities within Cusuco National Park; a buffer zone in which some human activity, including coffee plantations, is allowed, and the core zone in which no disturbance is permitted. Genetic diversity was assessed using intersimple sequence repeats, a technique similar to random amplification of polymorphic DNA (RAPD). I also measured various habitat variables including foliage height diversity (FHD), fruit availability, canopy cover, aspect of slope and angle of slope in the two sites. I found that FHD and fruit availability differed significantly between the two localities, with the buffer zone having higher values for both. Despite these differences in habitat, we found no significant differences in the level of genetic diversity between the two locations for either bat species. This may be because effective population sizes of the bats do not differ significantly between the sites, because of a lag between disturbance and population decline or because migration is sufficiently frequent to homogenize allele frequencies between the localities.