Cockatoos

["Philip Veerman" <>]

Hi Julian,

 

That is an odd comment about Sulphur-crested Cockatoos about Canberra, feeding in large flocks.  I have noticed in previous years that there are significantly less cockatoos around in the winter months.

The evidence from the GBS is very clear and very steady showing that numbers are highest in winter months. As in the graphs and text in the GBS Report (which is the reference for this sort of thing). This does have some possible bias that may be due to them being more in flocks during winter and thus easy to count larger numbers. Being such conspicuous birds, whether in small or large groups they are not missed, and so when less concentrated in warmer months with flock size smaller, there may well not be so much less abundant relatively, than what the GBS data clearly shows. Which is why it is essential that any publication of the GBS data come combined with a detailed description of the survey's history and methods explaining how the data were obtained, so that people can appreciate the challenges and biases.  

 

Philip Veerman

24 Castley Circuit

Kambah  ACT  2902

 

02 - 62314041

-----Original Message-----
From: Julian Teh [
Sent: Monday, 1 June 2009 5:37 PM
To:
Subject: [canberrabirds] Cockatoos

I have seen a lot of sulphur crested cockatoos about Canberra, feeding in large flocks. Sometimes these are infused with Long Billed or Little Corellas. Could this be a stock up on food before a migration? I have noticed in previous years that there are significantly less cockatoos around in the winter months.

Also, while on the subject, 3 large and well - fed looking Yellow Tailed Black Cockatoos flew into a tree in my back garden - They appeared to be feeding off dead leaves. I found this strange, but there were no berries or seeds in the tree. has Anyone else observed this? They seemed unfazed by my sudden appearance (For I didn't know they were there) out of the back door, and let me observe them from a close distance. 

Julian

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