Myna traps and numbers

["Philip Veerman" <>]

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.  

 

Philip Veerman

24 Castley Circuit

Kambah  ACT  2902

 

02 - 62314041

-----Original Message-----
From: martin butterfield [
Sent: Tuesday, 16 June 2009 6:04 PM
To: Julian Robinson
Cc: canberrabirds chatline
Subject: Re: [canberrabirds] Myna traps and numbers

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.

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.

Martin

On Tue, Jun 16, 2009 at 11:42 AM, Julian Robinson <> wrote:

For info...  Minister Hargreaves has learned from CIMAG that "Indian Myna numbers have been plummeting".   I'd have thought from the graph presented by Martin the other night that plummeting might be too strong a word.
Julian

PRISONERS TRAP MYNA BIRD MENACE

Published: June 16, 2009, 8:47 am
Section: John Hargreaves, MLA | Media Releases

Minister for Corrections, Mr John Hargreaves MLA, today announced that prisoners from the Alexander Maconochie Centre will provide much needed assistance to the Canberra Indian Myna Action Group (CIMAG) by constructing their specialised Indian Myna bird traps.

"I am very pleased to announce that ACT Corrections is incorporating positive environmental projects within the prisoners' daily schedules," said the Minister.

"Discussions have been taking place for a while between officers from ACT Corrections and CIMAG regarding the scoping and requirements for this trap construction project and I expect this endeavour to commence before the end of the financial year."

The Indian Myna bird is an invasive exotic bird species that takes over nesting hollows from native birds and small mammals. CIMAG formed as a community action group to reduce the impact of the Indian Myna on Canberra's native birds and animals. CIMAG will provide the discrete training necessary for prisoners to construct these traps. The skills gained through this trap construction program can be incorporated within the prisoners' Vocational Education Training programs.

"I am very supportive of the work that CIMAG has achieved to date through their Indian Myna trapping program," said Mr Hargreaves.

"When CIMAG originally formed in 2006, the Indian Myna was the third most abundant bird species in Canberra. Since that time, I have been pleased to learn that their numbers have been plummeting,' he said.

"The recent Garden Bird Survey conducted by the Canberra Ornithologists Group has seen this invasive exotic species drop to the twelfth most abundant bird species in our gardens," stated the Minister. "This is no small achievement by CIMAG and they are to be applauded for their efforts. However I am pleased to be able to support this ongoing project of CIMAG by having the prisoners construct these specialised traps."

"The work of the prisoners will help reduce the significant backlog in orders from the community for the traps.' said Minster Hargreaves.

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