Counting C Myna in GBS

To: "'Chris Davey'" <>, "'Sue Lashko'" <>, "'Paul Fennell'" <>, "'canberrabirds chatline'" <>
Subject: Counting C Myna in GBS
From: "Philip Veerman" <>
Date: Sun, 2 Jun 2013 12:10:17 +1000
May I remind everyone that the USE of the garden is explicitly not a criterion for counting for the GBS. Mainly because to do so simply creates confusion (or different opinions) between people, as to what constitutes "use". The criterion is only a detected and identified presence within the designated part of geography, within the time period. See this part of the instructions, that has been on every chart since 1993:

Instructions for Filling in the Garden Bird Survey Chart:

·       Write your name and identifiers in the white boxes. The starting day for each week is listed at the top of the chart. For convenience, write the day matching those dates in the white box. In leap years, week nine has eight days, then the starting day changes to one day later. If you make no observations for a particular week, clearly cross out that week number and date at the top and leave the column blank. Decide on, and keep to, a survey area equivalent to a 100 metre radius (3.1 hectares) from house/work and include only observations from within or over this area. There is no altitude limit, and no requirement for the birds to be 'using' the area.

·       For each species observed (heard or seen), record the maximum numbers of individuals occurring in the area at any one time within that week. When you do not know the actual number, record your best estimate, do not leave the record blank. At the end of each week, work down the chart so as not to miss out species. Only write one number and breeding code, no zeros, ticks, dashes etc., please. List additional species using their standard names in the spaces provided. Submit any rarities forms promptly.


As for the Myna e.g. I agree with everyone else, mostly probably with Julian. In Paul's question, if that is the only bird, the answer is clearly 1. Also note there are no zeros included as counts in the GBS.
I think the bigger question is if you have for example 15 Mynas in a trap and then 30 enter your garden, should the GBS number be 30 or 45? In that case the issue is does the restraint of the 15 influence the presence of the 30? If on the best of the observer's ability to detect, the mynas were free before being trapped at the time the other counted mynas were also in the GBS area, then you would count them allIf not, maybe it is biased, to record 45, rather than 30, because the 15 birds that were trapped means that it artificially allows or even attracts additional birds in the area. Just in the same way that you don't add the number of migrating honeyeaters that were in the area one minute earlier to the number come in in the next flock. In every case however I suggest that there is likely to be many more birds in your GBS area (3.1 hectares) than what you detect in your own garden, so the true numbers are often more than what is observed. 
In the end, I don't think it matters a huge amount what the precise answer is. The numbers get pooled and averaged and a count up or down by a small number either way is not a big issue. Far more important that we get as much coverage as possible from more contributors from more suburbs. I would not like little questions like this to put off people from contributing because they think it is too hard.
I am reminded that about a year ago I wrote a similar question about being at Kambah Pool and seeing someone release a Red Wattlebird he had caught raiding his fruit trees. As I did not record any other Red Wattlebird at that site that day and if I had not seen the man open the box and the bird fly out, I would not have known how it got there. I asked 'canberrabirds chatline' should I record it. I got inconsistent answers to that one too - and as I recall I did not put in any record sheet.
-----Original Message-----
From: Chris Davey [
Sent: Sunday, 2 June 2013 11:20 AM
To: 'Sue Lashko'; 'Paul Fennell'; 'canberrabirds chatline'
Subject: RE: [canberrabirds] Counting C Myna in GBS

The count is about the birds that use your garden.  Birds can use a garden in all sorts of ways. If it happens to use it to die then it still gets counted.




From: Sue Lashko [
Sent: Sunday, 2 June 2013 9:55 AM
To: Paul Fennell; canberrabirds chatline
Subject: Re: [canberrabirds] Counting C Myna in GBS


It was alive and in the GBS when trapped - no different from you seeing a bird in the GBS and then the cat eating it!



On Sun, Jun 2, 2013 at 9:44 AM, Paul Fennell <> wrote:

Hi everyone


To me, this is akin to Schrödinger’s cat, but with a practical aspect.


I one traps a Myna bird and disposes of it.  Does it appear on the GBS Chart as a one or a zero?






Paul Fennell

Editor Annual Bird Report

COG Databases Manager


026254 1804




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