Terns, now raptors, in Southern Moreton Bay.

Subject: Terns, now raptors, in Southern Moreton Bay.
From: Peter Woodall <>
Date: Mon, 23 Oct 2000 15:15:51 +1000
At 14:17 23/10/2000 +1100, you wrote:
>Thanks for posting your report Peter.
>Can I ask you a question.
>Why do the raptor numbers fall after the winter period?
>Thank you

Hi Paul

It  is mainly the Whistling Kites, and to some extent the Brahminy Kites,
that show these seasonal changes. (They are the dominant species anyway).

On my standard route, raptor numbers go from c. 230 in winter to 60 or less
in summer.  This pattern has repeated for two years in S. Moreton Bay and 
for two years previously in Pumicestone Passage to the north.

Why ? These are just guesses at this stage and other suggestions would be

Most of these raptors breed in winter, presumably when  food is most
available. This may be associated with fish, like bream,  spawning at this
Maybe food becomes scarce in summer and they have to move on.

Where to they go - who knows?

If it were just the Whistlers, we could suggest that they might be moving
but that would be less likely to apply to the Brahminy Kites.

Just a few of life's many mysteries.


Dr Peter Woodall                          email = 
Division of Vet Pathology & Anatomy             
School of Veterinary Science.             Phone = +61 7 3365 2300
The University of Queensland              Fax   = +61 7 3365 1355
Brisbane, Qld, Australia 4072             WWW  =
"hamba phezulu" (= "go higher" in isiZulu)


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