Wing morphology, echolocation, and resource partitioning in syntopic Cuban mormoopid bats

Abstract

In this study we combine analyses of wing morphology, echolocation calls, and temporal and spatial activity patterns to explore mechanisms of ecological partitioning among 4 syntopic Antillean mormoopids (Pteronotus macleayii, P. parnellii, P. quadridens, and Mormoops blainvillei). We captured bats with mist nets and harp traps, and monitored bat activity using automated Anabat systems for 31 nights at Sierra del Rosario Biosphere Reserve in Cuba. The wing morphologies (very low wing-loading and average-aspect ratio) and echolocation calls (broadband steep frequency-modulated calls at high frequencies) of all 4 species suggest that Cuban mormoopids are adapted to slow maneuverable flight, adequate for hunting insects by slow aerial hawking in background-cluttered habitat. However, our data show that each species has a combination of wing and echolocation call characters, presumably reflecting differences in their foraging behavior and microhabitat use. All 4 species were present at the 3 sampling sites and a majority showed similar activity rates at each site. Thus, we did not find strong evidence of spatial segregation during foraging. However, overall activity levels were higher in the primary forest when compared with 2 secondary-growth forests. Most pair-wise comparisons of temporal activity patterns between species were significant, suggesting high levels of temporal segregation. Our data suggest that wing morphology, echolocation call structure, and temporal activity patterns are morphological and behavioral factors that could facilitate resource partitioning among the Cuban mormoopid bats.