Help with night caller ID

[Evan Beaver <>]

Sorry Bob, I can't help you directly, but your e-mail does raise a point I've wondered about before. Can humans hear the echo-location noises of bats? Is it not too high, out of our frequency range? 
Well I've just answered my own question... consulting Menkhurst and Knights Mammals guide The yellow bellied sheathtail bat's "echolocation calls can be heard by some people". Continuing through the guide I can't find any bats likely to be in the area and have that call. None of the voices recorded notice any change in the echo calls; ie they are all regularly spaced and toned. I suspect this would make echolocation easier, using a different noise each time would be hard to process. So tentatively rule out a bat. Crashing into foliage might indicate some sort of glider? I'll keep reading and see what i can find.
Evan

On 1/19/06, Robert A Gosford <> wrote:

Dear all,
I'm wondering if anyone on the list might be able to assist with ID of the following call.
I live in a closed Eucalypt forest close to the coast at Vincentia on Jervis Bay, south coast of NSW. For the last few weeks I been hearing a call at night and been unable to spot the caller with a torch or against the (fairly bright though overcast this morning) night sky.
The call consists of about 8-9 closely-spaced but distinct notes and sounds like a trill or whistle. In this morning's wet forest and when the caller is some distance away it sounds quite high-pitched and almost ventriloqual - this may be through reflection off the wet leaves, though when the call is made closer there is a more distinct 'breathy-ness' and lower-range content to the call. The first note is slightly longer and lower than the following notes which do not change in pitch. I have heard the call repeated with some time between repeats or, as in this morning at 4.45am, repeated at variable times as close as a few seconds apart. The caller is highly mobile and moves quickly between trees. I have also heard the same call made elsewhere up the ridge behind or house - so the call may be a contact call, rather than say, a prey-finding echo-location call from a bat.
The caller appears to be foraging in the outer foliage of the Eucs as I can hear it crashing into foliage.
I think it is a bird, though none of the usual suspects come readily to mind - but it could be a bat or some other mammal.
Any assistance will be greatly appreciated.
Bob Gosford
Bhwerre
NSW
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Evan Beaver
Lapstone, Blue Mountains