Vanilla Bats: Insectivorous Bat Diversity in the Vanilla Agroecosystems of Northeastern Madagascar

Abstract

Due to global agricultural expansion and intensification, many animal species must now survive within a landscape dominated by agroecosystems. For bats, agroecosystems can provide a valuable foraging-habitat, and many species of bats thrive within such habitats whilst also providing a range of ecosystem services for farmers. Despite this, bat usage of many agroecosystem types remains unstudied. Here, we investigated the diversity of insectivorous bats in the vanilla agroecosystems of northeastern Madagascar, the world's principal vanilla-growing region. To assess bat diversity, we used a passive acoustic survey technique, and we identified and classified bat species diversity using PCA and DFA analysis of echolocation call acoustic parameters. In total, we were able to detect the presence of at least 13 different bat species within Madagascar's vanilla agroecosystems, seven of which we were able to confidently identify to species level. However, due to our conservative classification approach, the true diversity of bats in vanilla agroecosystems is likely to be higher. The results of this study indicate that Madagascar's vanilla agroecosystems represent suitable foraging habitat for numerous bat species, particularly forest-specialists, which is a highly encouraging finding for the conservation of Madagascar's bats. Expansion of vanilla agroecosystems is therefore likely to provide valuable habitat extensions for Madagascar's forest bats in the future, provided this expansion does not come at the expense of existing largely-undisturbed natural habitats.