This is forwarded from Rob Magrath, [EMAIL PROTECTED] ------------------------------------------------
We have been studying alarm communication in birds, and at least two species of small passerine respond by fleeing to cover after playback at natural amplitude of aerial alarm calls with a mean peak frequency of 9.1 kHz. Both white-browed scrubwrens and superb fairy-wrens fled after playback of either species' alarm call. The scrubwren's calls has a mean perk frequency of 7.1 kHz and the fairy-wren 9.1 kHz. As Michael says, it would be surprising if birds couldn't hear biologically salient vocalizations. Details of the alarm calls playbacks are in: Magrath, R. D., Pitcher, B. J. & Gardner, J. L. 2007. A mutual understanding? Interspecific responses by birds to each other's aerial alarm calls. Behavioral Ecology, 18, 944-951. Cheers, Rob Magrath [EMAIL PROTECTED]
