Hunting Strategies and Echolocating Performance of Bats — Quantitative Behavioral Laboratory Analysis
Two bat species, Megaderma lyra and Myotis myotis, were tested behaviorally for the efficiency of their echolocation system. Bats were conditioned to discriminate between two targets, plastic plates with identical pattern of holes of different depths. M. lyra performed 75% correct choices, with hole depth of 8 mm (+) against 6 mm (-). M. myotis succeeded in 87% of flights with depth of 4 mm (+) against 3.2 mm (-). However, the combination of 8 mm and 7.2 mm yields only 68% correct flights. Since the discrimination threshold depends not only on the depth difference, but also on the absolute depths, it is suggested that the bat evaluates small differences in the power spectra of the echo.