Environmental heterogeneity and water availability shape the structure of phyllostomid bat assemblages (Mammalia: Chiroptera) in the northeastern Amazon forest

Abstract

The relationship between environmental heterogeneity and species diversity has been one of the most studied patterns in ecology. However, some taxa and regions worldwide still lack studies to verify this relationship. Phyllostomidae is the most ecologically diverse family of mammals worldwide, encompassing a great proportion of the species of mammals and bats across the Amazon forest. Even though the Amazon seems to be a homogeneous landscape with an unlimited supply of water, it presents a high variation in vegetation types and proximity to large bodies of water. In our study, we have analyzed the relationship between environmental heterogeneity and proximity to large bodies of water in the structure of phyllostomid assemblages (Chao-estimated species richness and capture rates). We have found that an increase in landscape heterogeneity associated with large bodies of water and representative flooded forest increase species richness. In addition, more heterogeneous landscapes in the presence of water have presented a higher abundance of bats. Our findings might be related with the small niche widths of phyllostomids, which could have promoted specialization in some landscape features, while the presence of water could have promoted an increase in food availability (insects and fruits), leading to an increase in phyllostomid richness and abundance. This is important information for planning where to place protected areas in the northeastern portion of the Amazon, while taking into account the consequences of drought and deforestation close to water bodies on the local phyllostomid fauna, and the maintenance of the ecosystem services provided by a higher bat diversity.