Little Corella

To: <>
Subject: Little Corella
From: "Philip Veerman" <>
Date: Sun, 1 Apr 2012 12:54:35 +1000
I don't know why but my computer would not open Martin's attachment, so I will just imagine that it would show the A values over the years (which I think I can accurately do). I think the data would support the comments, with these 2 disagreements. That Cockies are still a long way in front is surely true, but that truth is simply where we are in history right now. Difference in total numbers in no way reduces the strong possibility that the massive increase in the Corella population is contributing to the decline in the Cockatoo population. If the trend continues, the trend itself may become self sustaining. I'm not saying that is the cause, only that it is highly likely to be a factor. They compete on all levels. That TV show about Carnaby's Cockatoo showed that galahs & corellas compete with them too. I also don't see a need to invoke the suggestion of recruiting from outside, even though it is possibly happening (or more likely in the previous dry years). As the trend once started could occur just as well even if Canberra was an island.
Isn't it good that someone decided in 1989 to compile the GBS data as the basis for a report on it...........
-----Original Message-----From: Con Boekel [ Sent: Sunday, 1 April 2012 9:48 AM      To:
Subject: Re: [canberrabirds] Little Corella

Looking at those graphs it seems to me possible to hypothesise that if the later years are the start of a trend, then the Little Corellas are gaining while Sulphur-cresteds are declining, relatively. I suppose that one of the variables is how much the Little Corellas and Sulphur-cresteds are recruiting from outside.
What the graphs do show is what a wonderful resource long-term data collection by way of the GBS is.

On 1/04/2012 9:39 AM, martin butterfield wrote:

I think the answer is probably not.  The attached GBS based graph shows that the Corellas have  - as you indicate - made a massive increase in the recent past, but while the Cockies have a slight downward trend from a high point, they are still a long way in front.  The graph also served to jog my mind about how far Cockies have increased in the past 30 years.

In Ian Fraser's latest book he wonders if Corellas will overtake Galahs (the latter having themselves only arrived in this area in the last ~60 years).


On Sun, Apr 1, 2012 at 9:00 AM, Con Boekel <> wrote:
This morning a flock of 170 Little Corellas flew over Haig Park in Turner. It is obvious that Little Corella numbers in Canberra have climbed over the past quarter of a century - certainly in the Inner North. I often notice Little Corellas feeding in the same trees as Sulphur-crested Cockatoos - on the same food.

The question I have is this - are our Sulphur-crested Cockatoos declining as the Little Corellas increase?
<Prev in Thread] Current Thread [Next in Thread>

The University of NSW School of Computer and Engineering takes no responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the Canberra Ornithologists Group mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the list contact David McDonald, list manager, phone (02) 6231 8904 or email . If you can not contact David McDonald e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU