Acoustic Behavior and Feeding in Glossophagine Bats

Hearing sensitivity and ultrasonic vocalization in glossophagine bats were investigated as they relate to an anatomical and behavioral continuum from insectivory to nectar and pollen feeding. The performance of four species in obstacle avoidance tests indicates that the more insectivorous members of the subfamily can detect wires of equivalent diameter to those reported for Myotis, whereas those bats which interact exclusively with chiropterophilous plants exhibit inferior performance. Hearing sensitivity as measured by cochlear potentials does not reflect the dietary habits, but supports a view of polyphyletic origin for the subfamily. The data suggest that although target detection depends on multiple factors, the sound-producing mechanism of these bats is more open to selective modification through ecological pressures than is the receiver.