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Raven calls

To:
Subject: Raven calls
From: Graeme Chapman <>
Date: Sun, 17 May 2015 11:50:51 +1000
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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