Regarding the possible ultrasound from a White-throated Nightjar or
Owlet-nightjar, I've now had an opportunity to look at the sound
recorded on tape through the Anabat detector. At the point where Ray
Leggett annotates the tape "Owlet-nightjar, question mark", the
preceding train of ultrasound pulses are those typically made by a small
vespertilionid microbat. Even though I am not intimately familiar with
the bat calls of southeast Queensland, it's fairly clear they are of a
Broad-nosed Bat (Scotorepens sp.), and most likely the Little
Broad-nosed Bat (S. greyii). It must have been a coincidence of the bat
flying past unseen and being recorded as the nightjar came into view.
There's no doubt that the only sound recorded is that of a typical
microbat. I have a TIFF file of the graphical display of the call; if
anyone is interested in seeing it, drop me an e-mail & I'll attach it .
Lawrie Conole
Geelong, Victoria, Australia
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