In reply to Frank's questions re Noisy Scrub-birds:
1) Annual censuses are done by mapping singing males. Usually this is done
by listening, rather than playback, because playback could induce a bird to
an area where it might not normally be (the mapping has to be quite
accurate).
2) Males caught for translocation are attracted to a mist net by use of
taped calls. Usually, one only gets ONE chance to catch a given male - if
you don't catch him the first time, you have usually lost your chance. If
birds were habituated to hearing taped calls, this could become a problem.
All birds caught to date have come from two Peoples Bay, and this situation
is unlikely to change in the forseeable future. However, the population at
Waychinicup/Manypeaks (started from a translocation) is now somewhat larger
than the 2People Bay population.
3) There is as yet no experimental evidence, but observations in aviaries
suggest that males that get more food sing more, and vice versa. Or, to put
it another way, it is possible that if a male is spending too much time
investigating taped calls, he may miss out on feeding time, but I don't
know how likely this would be. They do seem to put a lot of energy into
producing territorial song. Incidentally, scrub-birds recognise their
neighbours' calls.
Cheers,
Allan
- - -
Dr Allan H. Burbidge E-mail OR
Dept of Conservation and Land Management,
Wildlife Research Centre,
PO Box 51, Wanneroo WA, 6065 Australia
Tel: +61 8 9405 5100 Fax: +61 8 9306 1641
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