Ian Martin wrote:
> A question I'm trying to answer is, can you easily distinguish between
> an original bird call and an imitation of that call eg by a
> lyrebird ie
> does the call just sound the same to us (and have a different
> sonogram)
> or are the sonograms virtually the same as well?
That's a very interesting question Ian! A lyrebird master singer can
give a mimicked call that is not easily distinguishable from the
original. The sonograms are pretty much the same, altho I have still
to do a comprehensive study on that. A learning lyrebird sometimes
gives a slightly wobbly mimicked call, and sometimes a mimicked call
starts out one way then morphs into a different species' call, so
that's a dead giveaway. The best way to pick the lyrebird is that
all the mimicked calls are coming from a single spot and usually on
the ground. And of course the lyrebird adds its own territorial
songs and other lyrebird-only calls.
Stereo recordings could be useful for unmanned surveys of Rufous
Scrubbirds, i.e. so that you could tell the direction of the calls.
Vicki Powys
NSW
On 11/11/2011, at 10:20 AM, Ian Martin wrote:
> Hi Peter,
>
> Raven Lite will not only take a number of digitally recorded formats
> from you recorder via a computer, but also read calls from any
> commercial CD and hence you can supplement the disk provided with the
> book, with Oz recordings eg the BOCA set or the sets by Fred van
> Gessel
> etc. The book's CD has its main use with the examples used in the
> book,
> allowing you to listen to and (using Raven Lite) simultaneously
> observe
> the sonograms while you read the comments. The book and CD by the
> way is
> not meant to be a sonogram based catalogue of US bird calls but rather
> it is a collection of those calls which are described in the book and
> form parts of the authors research over the years.
> IMHO the main use of the book is to give you ideas about some of the
> uses of bird call sonograms.
>
> If you access to them the HANZAAB books have (very small) sonogram
> examples with many species - but be aware - some birds only have
> one of
> two different calls (eg Eastern Whipbird) but others have literally
> thousands of variations (see the book) ... and some calls can also
> change with time and with interactions with other birds.
>
> A question I'm trying to answer is, can you easily distinguish between
> an original bird call and an imitation of that call eg by a
> lyrebird ie
> does the call just sound the same to us (and have a different
> sonogram)
> or are the sonograms virtually the same as well? This has a practical
> application with bird surveys using recorded sounds. At present a
> group
> associated with the Hunter Bird Observers Club (HBOC) is monitoring
> some
> rufous scrub birds using specialised waterproof recorders which can
> record for days or even weeks unattended in the rainforest. RSB's are
> easy to detect when they use their own characteristic chipping
> calls etc
> but they also mimic other bird calls and sounds at times - is the
> recording an RSB mimic or the real bird?
>
> Ian
> -----
> Ian Martin Newcastle, NSW, Australia
>
>
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