Abstract Coexistence among Neotropical insectivorous bats (IB) that share roosts, foraging areas, and prey likely relies on processes promoting trophic niche divergence. We examined the diet and activity times of 3 coexisting IB species (Molossus molossus, Neoeptesicus furinalis, and Myotis nigricans) in Venezuelan rice fields in Northwestern Llanos to assess dietary and temporal overlap. Using published sources, we categorized prey by hardness and flight speed, bats by bite force and functional group, and examined the relationships among these variables. IB species showed differences in prey composition, type, and activity timing. As expected from its fast flight and strong bite, diet of M. molossus consisted primarily of fast-flying, highly sclerotized insects, with activity times peaking significantly earlier than in the other 2 bat species. In contrast, M. nigricans and N. furinalis had diets consisting primarily of slower-flying prey and showed high temporal overlap in activity, although with different peak foraging times. Notably, the stronger bite of N. furinalis may have enabled it to exploit more sclerotized prey than M. nigricans, despite similar flight capabilities—indicating that prey hardness helps reduce dietary overlap. These findings suggest that fine-scale trophic niche partitioning, enhanced by the rich insect fauna of rice fields, facilitates the coexistence of these ecomorphologically distinct IB species.
Romero et al. (Sat,) studied this question.