| I used 918 playback presentations in the field to three species of vespertilionid bats to assess the influence of echolocation call design and foraging strategy on the role of echolocation calls in communication. Near feeding sites over water, Myotis bats (M. lucifugus and M. yumanensis) responded positively only to conspecific echolocation calls, while near roosts these bats were unresponsive prior to 30 June. Newly volant young (post 30 June) responded positively to presentations of echolocation calls of similar and dissimilar design. At feeding sites Lasiurus borealis, which foraged at permanent floodlit sites, responded only to conspecific calls and particularly to feeding buzzes. While Myotis, particularly juveniles, are thought to use the echolocation calls of conspecifics to locate feeding sites, L. borealis appears to use the calls of a foraging neighbour attacking prey to identify opportunities for pirating food. |
