Bats in Costa Rica

Phyllostomid Bats in Costa Rica

Our research investigates structural and functional connectivity for important frugivorous and nectivorous bat species (Phyllostomidae) in the San Juan-La Selva (SJLS) biological corridor in northern Costa Rica. Bats are an ideal taxon for addressing native species’ response to forest fragmentation and land use change in the matrix between habitat patches in fragmented landscapes. Of the 139 mammal species in the SJLS, 79 are bats. In addition, nectivorous and frugivorous bats are the primary seed dispersers and pollinators of hundreds of tree species, and thus play a key role in sustaining plant biodiversity. Fragmentation and land use change in the matrix, especially agricultural intensification, may present a significant challenge for bats to maintain reproductive connectivity within their own populations as well as for associated mutualistic tree species. Given their diversity, abundance, and key role as seed dispersers and pollinators, measuring how well bats are able to move through human-dominated landscapes for foraging and reproduction is an important component of estimating overall ecological resilience.

We use both established field methods and innovative genetic techniques to investigate structural (i.e., patch size and isolation) and functional (i.e., permeability of the agricultural matrix) connectivity for Phyllostomid bats at both the community and species level. At the community level, we aim to compare bat species richness, diversity, and relative abundance in continuous forest with these same metrics in patches of differing size and isolation and embedded in different land cover types.  At the species level, we focus on two frugivorous species of differential mobility, Artibeus jamaicensis and Carollia castanea.  For these species, we are using microsatellite markers to compare genetic diversity within and gene flow between forest patches of differing size and isolation and embedded in different land cover types.  We are also using mitochondrial DNA markers to characterize historical genetic variation in these two species in the SJLS, which will improve our estimates of the proportion of genetic structure attributable to recent land use change.

This project will make an important contribution to wildlife conservation in human-dominated landscapes and develop methodologies applicable to any human-dominated landscape worldwide. This work is part of a larger interdisciplinary project focused on quantifying social and ecological resilience in the SJLS.