Geoff is right to use the F statistic
number of sites (though F expresses this as a %) in this little analysis. One of the many outputs I designed for the GBS was to automatically select the top 50 (or any other
number) from the last 5 (or any other number or arrangement of years but last 5 seems a good moving average) and sequence them in the right order this was so as to have an immediate output for arranging the species list for the next printing of the GBS Chart.
It seems that this has not been used.
The incursion of sites involving wetlands sufficient to have the impact on A values of waterbirds, is a relatively new thing in GBS history, so there is not
a lot of value to be had from that comparison (until including that knowledge). I did not know that
King Parrots were exceptional, then (1959), in Canberra
but extrapolating the graph in the GBS Report back that far certainly supports this, as the increase has been steady from being initially rare over that time.
Philip
From: Denis Wilson [
Sent: Wednesday, 1 June, 2016 2:57 PM
To: Geoffrey Dabb
Cc:
Subject: Re: [canberrabirds] and now, GARDEN BIRDS
Thanks to Geoffrey Dabb for his draft Christmas Card.
It reminds me that a number of those birds would not have been on the typical Canberran garden birds lists when my family moved to Canberra in 1959.
... Crested Pigeons were seldom seen east of Harden Murrumburrah back then.
... King Parrots were exceptional, then, in Canberra.
... And Pied Currawongs were then regarded as "vertical migrants", coming in to the suburbs from the tall forests in winter.
Denis Wilson (Feeling like a Time Lord today)
On Wednesday, 1 June 2016, Geoffrey Dabb <> wrote:
Still on the subject of the ABR for 2014-2015, the GBS table is always of interest. The top 12 species might make a suitable Christmas card to send to non-Canberrans later this
year. For the ‘top 12’ I believe the number of sites is the appropriate qualification. If you use ‘abundance’ you will find the Eurasian Coot is the 12th ranked garden bird although recorded at only 17.2% of sites and the Silver Gull is 21st
(9.4%). On the other hand all the below twelve species (not placed in order) were recorded at at least 90% of sites. You might compare this 12 with the top 12 woodland species, but to interpret the comparison you would need to bear in mind that some ‘garden’
sites take in significant areas of woodland (and wetland, apparently). Further down the list the Noisy Miner is lurking ominously at 59.4%. Give me the coots any day.
