Community and species-level responses of phyllostomid bats to a disturbance gradient in the tropical Andes

Understanding animal responses to habitat change and habitat loss is central to the development of conservation and management strategies. Behavioral responses could allow for early detection of animal responses even to small scale disturbances, becoming of increasing importance for conservation. Here, we explore the effects of a low to moderate disturbance gradient on a phyllostomid bat assemblage in a tropical Andean forest of Bolivia, focusing on both community-level (changes in species richness and composition) and species-level (temporal and spatial activity patterns) responses. Although few differences were found in bat assemblages along the disturbance gradient, strong changes in behavioral patterns were noted; activity patterns varied spatially and temporarily. Spatially, some species increased their activity in more disturbed areas whereas others concentrated their activity towards more forested areas. Temporally, niche overlap among frugivores varied along the disturbance gradient: higher temporal niche overlap occurred in disturbed areas whereas a more segregated temporal pattern was observed in forest habitats. Nectarivores did not change their temporal niche patterns, but they segregated their activities in space. Altogether, our results suggest that comparisons based only on community-level responses might be misleading, failing to detect effects of habitat conversion when organisms are actually responding to disturbances.