Arrival dates of Galahs and Sulphur-crested Cockatoos

To: "Birding-Aus" <>
Subject: Arrival dates of Galahs and Sulphur-crested Cockatoos
From: "Philip Veerman" <>
Date: Thu, 21 Sep 2006 15:09:14 +1000
Hi All,
I think it odd that there is a suggestion that Galahs and Sulphur-crested 
Cockatoos are in lower abundance in winter around Orange etc. In Canberra, 
which surely is more consistently cold in winter than the areas described, both 
species have a recording rate that is virtually constant throughout the year. 
That is to say that the Galah certainly does have (see figure 12, page 31, in 
my 21 year GBS Report). I'm sure the ScC would be similarly consistent in 
recording rate. Whilst recording rate is constant, abundance changes. Both 
species show a very regular pattern of annual changes in abundance. They both 
have the minimum in spring and maximum in winter here. The pattern for the 
Sulphur-crested Cockatoo is smoother than that of the Galah, which has a 
shorter low abundance period. All details from my book: "Canberra Birds: A 
Report on the first 21 years of the Garden Bird Survey". This is based on 1316 
observer years of data.


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