Dear All,
We are facing a problem that some of you may have already come upon and solved,
so I am taking the liberty of asking...
The thing is, we have to make recordings of the sounds of peanuts being handled
by foraging Mexican jays. The birds frequently lift peanuts and then for a
moment rapidly open and close their beaks on them, thus knocking on the shell.
As some peanuts are then discarded, and some accepted (either eaten on the spot
or cached), there is a possibility that the sound helps the birds asess the
contents of nuts. To learn more about this we have to make recordings of the
birds knocking on peanuts that may sound different (e.g. full vs. empty shells
etc.). The quality of the recordings should, naturally, allow for comparison of
sound properties. Recordings of ourselves knocking on a peanut with a magpie
bill mounted on tweezers suggest that the microphone should be really, really
close to the bird. As we are going to record free-living birds, this does not
seem too simple to achieve.
We are considering the use of:
- a boundary microphone buried among nuts (but then birds can easily step on it
ruining the recording) or under the nuts (but what sort of membrane would be
strong enough to hold a bird - or birds - and not distort or attenuate the
sound in any way?)
- a small microphone hanging from a branch over the feeding arena (but then
probably wind would spoil most of the recordings)
- a shotgun aimed at the scene
- a parabolic microphone aimed at the scene...
And so, obviously, we would greatly appreciate any suggestions or comments you
may have, any pros and cons you may come up with. We are talking about
frequency range 0-15 kHz, at least.
Thank you very much in
advance,
Maciek Fuszara
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Maciej Fuszara, PhD
Faculty of Biology
Cardinal Stefan Wyszynski University
Woycickiego 1/3
01-938 Warsaw, Poland
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