Roosting and Foraging Behavior of Two Neotropical Gleaning Bats, <i>Tonatia silvicola</i> and <i>Trachops cirrhosus</i> (Phyllostomidae)¹

Abstract

ABSTRACT We studied roosting and foraging behavior of two Neotropical gleaning bats, ďOrbigny's round‐eared bat, Tonatia silvicola , and the fringe‐lipped bat, Trachops cirrhosus (Phyllostomidae). Techniques included radio‐tracking in a tropical lowland forest in Panama and analysis of data from long‐term studies in Panama and Venezuela. Day roosts of T. silvicola were in arboreal termite nests. T. cirrhosus roosted in a hollow tree. T. silvicola emerged late ( ca 60 min after sunset), and foraged close to the roosts (maximum distance 200–500 m). T. cirrhosus emerged early ( ca 30 min after local sunset), and foraged farther from its roost (&gt;1.5 km). Both bats used small foraging areas (3–12 ha) in tall, open forest. They foraged in continuous flight (maximum 27–36 min) or in short sally flights (&lt;1 minute) from perches (“hang‐and‐wait” strategy). The small foraging areas of these bats and their sedentary foraging mode most likely make them vulnerable to habitat fragmentation.