Use of forest strata by bats according to wing morphology and habitat complexity in a fragment of tropical dry forest (Colombia)

Abstract

The high spatial heterogeneity of tropical forests is one of the main causes for its vast biodiversity, along with other factors such as resource partitioning and habitat structure. Bats are a major component of these ecosystems and provide different functional roles and ecosystem services. This aspect is especially important in highly fragmented environments such as dry tropical forests, where the mechanisms that control the structuring of bat assemblages in these environments are still unknown. The present study examined the use of forest strata by a bat assemblage, which was evaluated throughout 16 nights of sampling during the rainy season (September 2009) in a tropical dry forest in Colombia. Using elevated and ground mist nets, a total of 170 bats from 13 different species were captured. Of these, 110 individuals and four unique species were captured at the Available Height for Foraging (AHF) (5.4-8.4 m) and 60 individuals and five unique species at the understory height (0-3 m). Variation in the vertical distribution of bat species revealed differences in feeding habits and foraging strategies, demonstrating species-specific patterns on how bats move through the forest according to leaf density and wing morphology. A possible relationship was detected between the wing aspect ratio and the forest layer in which the bats forage, probably according to food resource distribution, which has the potential to influence the structure of bat assemblages, and of the functional dynamics of these animals in tropical dry forests. assemblages (Pereira et al.