Our resident male Cassowary has not been seen since Sept 25 and we
think he has finally gone off to nest, after a couple of months of
sporadic mating with the female and one short absence, which might
have been a failed nest attempt during the peak of the cold weather.
Just before he went, on Sept 21, Sue witnessed an unusual activity
from the big female "Missy"-
She sat down and gave a very long continuous deep throbbing call,
something like a minute in duration, which we believe is a mating
call, not the usual contact note. It is so deep as to be felt as much
as it is heard, and is presumably what i perhaps mistakenly used to
call ultrasound but is now seemingly infrasound, the same as deep sea
vocalizations of whales that can travel huge distances, a useful
attribute in the dense forests we have here. The male appeared about a
half hour later and successful mating occurred, even being caught on
video by some of our guests- the teenage boys were quite impressed,
their mum less so! This might have been coincidence, but it is
striking that this odd vocalization was given beforehand.
Today the female was here alone, and gave 3 quite short but very deep
thrumming notes, with head lowered to below breast height, sort of
bowing down, and plumage really fluffed out. This was not in response
to any obvious external stimuli, she was quite relaxed, she just gave
this call which is unusual for her. The call was similar to that which
the male gives when he wants to gather up the chicks and move on, he
gives usually 3 and sometimes just 2 deep vibrating notes, slightly
higher pitched than those of the female, each note perhaps a second or
so long and interspersed by a couple of seconds. This 'moving on' call
is only given in that situation where the birds are about to move, so
you seldom hear it and I have lamentably still to tape it as i always
contrive to miss it, though our Japanese TV crew did get it on film
earlier this year when I was doing my David Attenborough bit.
It is interesting to note that there is a difference in the calls of
the sexes. Whether or not the keratinous but internally honeycombed
casque serves as a kind of amplifier remains to be determined, I would
not be at all surprised.
These deep toned vibrating notes are very different to the much
lighter toned and non-vibrating "whoomp" alarm of brush-turkeys, which
some folks think is the Cassowary call. The only comparable note I can
think of is with Eurasian and Australasian Bittern, where that deep
song note is right at the limits of my hearing these days and
presumably has a similar long-distance travel function.
Phil & Sue Gregory
Http://www.sicklebillsafaris.com
Http://www.cassowary-house.com.au
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