Yes, I agree that they couldn't have been Forest Ravens.
I'm thinking they were in fact Aussies. It's just that I'm a little
surprised they occur there.
--------------------------------------------------
From: "Kev Lobotomi" <>
Sent: Sunday, May 17, 2015 1:51 PM
To: "Graeme Chapman" <>;
<>
Cc: <>
Subject: Raven calls
Also there is no chance the birds could be forest ravens. This is way out
of their range and the south gippsland birds do not wander that much. Kev
--- Original Message ---
From: "Graeme Chapman" <>
Sent: 17 May 2015 1:26 PM
To:
Cc:
Subject: [Birding-Aus] Raven calls
Hello Bill,
In my experience there is little variation in Australian Raven calls from
place to place all over Australia, except for the SW of W.A. where they
all sound distinctly different in pitch (Listen on my website under
Western Raven.) However if you are talking repertoire, Australian Ravens
have a call for almost every occasion. When they are chasing a raptor
(such as on call LS100104 on my website) they sound almost hysterical
whereas at rest (mild advertisement, at rest call) the calls almost
suggest the mood. When I hear that hysterical call, I always look at the
sky because I know there'll usually be a Wedgie or a Little Eagle up there
or sometimes a smaller raptor. The raven-like calls you heard may have
just been one you are not familiar with - for instance they have a quite
distinctive travelling call when flying high overhead which may be a
signal to the resident birds below that they are doing just that,
travelling, and have no territorial intents.
Little Ravens are a different story. Like Australian Ravens they do have a
repertoire, perhaps less distinctive to our ears, but there are other
variables. Birds from the interior are on average smaller than those from
alpine areas and to my ear, the bigger alpine birds have deeper sounding
calls . Little Ravens and Forest Ravens form a superspecies (that is they
are very closely related) and Forest Ravens, which are even bigger again
have even deeper calls. I like to think I've had more experience with our
crows and ravens than most people these days (I studied them with CSIRO
and Ian Rowley for nearly ten years) but I do admit that occasionally I
hear a corvid call that makes me think, as you did at Chum Creek. The ones
I have found most difficult were either from the Coorong/SE South
Australia or from south Gippsland, where both Little and Forest Ravens
occur together. Corvids vary a lot in size. Males are mostly bigger than
females by about 10% but the birds we used to call runts (the youngest of
a clutch of five that only survive in good seasons - normally they starve
and fail to fledge) go through life as much smaller birds and probably
sound like wimps as well!! I did handle a bird once which, on measurement
was midway between Little Raven and Forest Raven and I wouldn't be
surprised if one day somebody finds these two species as a mixed pair.
As somebody has pointed out certainly both Australian and Little Ravens
can occur at Chum Creek, and even Forest Raven would be a possibility -
the Prom isn't that far away and corvids do wander.
So you can see there are lots of variables and without hearing a recording
of your birds at Chum Creek, we'll never know. One thing I do know is that
Australian Ravens from Chum Creek will sound like Australian Ravens from
anywhere else in the eastern states. I am not aware of any local dialects.
That doesn't mean there aren't any - just that they are hard to discern.
As with any other passerines, most of their repertoire is learnt and like
the vowel sounds in humans, they would vary from place to place. If you
really want to hear regional variation in an Australian bird, go listen to
the Grey Butcherbirds.
Regards
Graeme Chapman
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