|To:||"'martin butterfield'" <>, "'Julian Robinson'" <>|
|Subject:||Myna traps and numbers|
|From:||"Philip Veerman" <>|
|Date:||Tue, 16 Jun 2009 23:39:39 +1000|
That is really good but I would like to see a dot point at each of the year values, that would make it a lot easier to see what the actual data were. As it is, it is not that easy to focus on the actual data unless there is a "kink" in the line (which only happens if two successive years have a different trend). A calculated curve is an abstraction, although possibly instructive.
We should not ignore the obvious (and I predicted it) although I haven't looked at GBS data that the Starling is rising again.
24 Castley Circuit
Kambah ACT 2902
02 - 62314041
-----Original Message-----For those who missed my chat the other night I have attached the graph to which Julian refers. It even has labels on the axes! For assessing the Minister's rhetoric it is better to focus on the blue line (original values) than the dotted, trend line.
From: martin butterfield [
Sent: Tuesday, 16 June 2009 6:04 PM
To: Julian Robinson
Cc: canberrabirds chatline
Subject: Re: [canberrabirds] Myna traps and numbers
Although the release of this data was nothing to do with me (I wasn't aware of the comments until pointed out to me on a run at lunchtime today) and it is rare for me to agree with any of the local politicians about anything, I do tend to think that 'plummeting' is a reasonable word. From the Common Myna's largest recent value of A ( I couldn't bring myself to say 'high point') at 4. 9587 in year 25 the value has declined by 52.3% in 2 years to 2.3611. For those of an actuarial persuasion I think this comes out to a compounding decrease of close to 31% per annum which is rather impressive.
Another way of looking at the outcome is that the value of A for Common Myna in 2007-08 is below that for the species in 1990-91! Again I reckon this is quite impressive.
The very highest values of A for this species occured in 2000-01 (year 20, 5.1588) and 1998-99 (year 18, 5.4021). As I inferred last week, I haven't attempted to explain the decreases between those years and year 25. However they were not as dramatic as that between years 25 and 27.
Perhaps COG should run a sweep on the value of A for year 28? Although I hate forecasting, if the decrease continues at the same % rate as for the last 2 years it should be around 1.6.
On Tue, Jun 16, 2009 at 11:42 AM, Julian Robinson <> wrote:
|<Prev in Thread]||Current Thread||[Next in Thread>|
|Previous by Date:||Myna traps and numbers, Leo Berzins|
|Next by Date:||Myna traps and numbers, Peter Ormay|
|Previous by Thread:||Myna traps and numbers, Leo Berzins|
|Next by Thread:||Myna traps and numbers, Peter Ormay|
|Indexes:||[Date] [Thread] [Top] [All Lists]|
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: email@example.com.EDU.AU