winterbirds 2011

To: "'Canberra birds'" <>
Subject: winterbirds 2011
From: "Philip Veerman" <>
Date: Thu, 30 Jun 2011 11:26:55 +1000
Very true. Before it happens I will mention, there is a cautionary note towards looking at GBS data for ideas on this. One relevant feature of the question is that the GBS calendar splits winters between years. That is why the question is easier addressed at least on GBS data for "summer migrants" than "winter migrants". Of course the COG ABR has always been on a July to June year also.
This is why on The GBS Report I did graphs of a different style (calendar year rather than financial year) for the winter migrants. (This is explained in detail on pages 29 & 30.) You will note that this system was used in Birds of Canberra Gardens edition 1 (because I supplied those graphs and the reason was given on page ix). In Birds of Canberra Gardens edition 2 there does not appear to be any such thought given to this issue. As far as I see it is not mentioned at all (at least as to why the two versions should differ) and all the graphs are labelled as calendar year, even though none of the data were collected or analysed as calendar year. Apart from that the squiggle obscures inter year variations anyway and I find it impossible to know what the data are. Page viii says that the graphs for the Silvereye and Grey Fantail look similar but I think whoever wrote that forgot to put on their glasses. If they wrote that the graphs for the Silvereye and Weebill (p 32) look similar, well then that would be sensible...........
-----Original Message-----From: Geoffrey Dabb [ Sent: Thursday, 30 June 2011 9:06 AM
To: 'Cog Chatline'     Subject: RE: [canberrabirds] winterbirds 2011

Yes, I think that’s a good example of variability.  The DWS is a variable migrant.


If I remember last Winter, I might say “Oh there’s lots of DWSs around all year”.  Perhaps that was also true for 2007.  Someone who bases their understanding on only a low year or two might say “It’s very unusual to see a DWS in Winter”.


BF Cuckoo-shrike is also highly variable.  Query pardalotes, orioles, YFHE etc.


What this means is comments on seasonal occurrence should have inserted “In some years … but in other years …”.


It brings us no closer to understanding typical/non-typical (if meaningful at all), or the nature of the trend, or the cycle, whichever it is.  


From: Roger Curnow [
Sent: Tuesday, 28 June 2011 8:28 PM
To: Cog Chatline
Subject: Re: [canberrabirds] winterbirds 2011


Hi Geoffrey


Out in H11 i  haven’t seen one Dusky woodswallow since June 1.

Last year I could find 37 (? haven’t checked my records) most days.






Sent: Tuesday, June 28, 2011 4:16 PM


Subject: RE: [canberrabirds] winterbirds 2011


Yes Tony – the summary of last year’s exercise is in the list archive for 3 August 2010.  There were 5 reports of reed-warblers for those 8 weeks, single birds at various locations.


My impression is that there are less of the targeted species around this year.  Whatever the actual temp readings, I think this Winter has a harder edge to it.


From: Tony Willis [
Sent: Tuesday, 28 June 2011 3:45 PM
To: canberrabirds chatline; Ian Anderson; David.Clark
Subject: [canberrabirds] winterbirds 2011


Last year Geoffrey Dabb conducted an interesting survey on birds that overwinter in Canberra but belong to species that are generally accepted as being migrants, that leave us in autumn and return the following spring. 

Last Saturday, 25th June, a group of us did a circumnavigation of Lake Ginniderra, and in the vicinity of the boat ramp at MacDermott Place we observed this Australian reed-warbler.  It was originally in the reeds but ascended a casuarina as we watched, apparently searching for food.  As far as I remember, it was silent the whole time.

I think it has been proposed previously that some A. reed-warblers might stay through winter but are generally overlooked as they are not calling through this period.  We reported an A. reed-warbler last year in the same location, on the 31st July.

Tony Willis

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