Diet of frugivorous bats and resource availability in a tropical dry forest of Northeastern Colombia

Abstract

Tropical dry forests are among the most transformed and threatened ecosystems in Colombia, where habitat fragmentation can alter resource availability and ecological interactions between plants and frugivorous bats. We evaluated the diet of frugivorous bats and its relationship with plant resource availability in a heterogeneous tropical dry forest landscape. Bats were sampled with mist nets across different vegetation cover types, including tropical dry forest remnants, pastures, and transition zones. Vegetation was characterized using sampling plots. Dietary interactions were documented primarily by identifying seeds present in fecal samples; two additional bat-plant links were documented through direct observations of fruit feeding. These records were used to build a bat-plant network describing the structure of trophic interactions. The network included seven bat taxa with records of fruit consumption, and interactions were concentrated on Artibeus planirostris and Sturnira tildae. The vegetation was composed largely of plant species typical of disturbed habitats and agricultural matrices. The interaction network had a connectance of 0.33 and specialization of H2’ = 0.38, with most interactions concentrated among generalist taxa. The most frequently recorded dietary resources were Piper sp., Cissus sp., and Muntingia calabura, highlighting their importance in the landscape. Several of these frequently recorded dietary resources were not detected in the vegetation plots, indicating that bats exploited food resources beyond the vegetation sampling units. Our results highlight the potential ecological role of frugivorous bats in fragmented tropical dry forest landscapes, where they may contribute to seed dispersal and vegetation regeneration despite substantial anthropogenic transformation.