Scarlet Robin and Thompson

[David Rees <>]

Paul

Very maybe.  If you look at the last 20 years worth of data on your graph  then the conclusion I would come to would be its 'bumping along' - the level of variation in the data over this period is probably 'noise' and certainly inconclusive. Clearly a 'significant long-term downward trend' this data set does not show.  This graph and the woodland data graphs are showing very different things - Why?  Is that not interesting?

David

On Fri, Apr 8, 2016 at 1:19 PM, Paul Fennell <> wrote:

Hello everyone

The graph is from the general surveys that COG collects since 1991.  I interpret it as a very gradual, but inexorable decline over the period.  The reporting rate is the percentage of survey sheets which report Scarlet Robins, divided by the total number of sheets submitted for the reporting period, converted to a percentage.  The area covered is the COG area of interest, although the majority of sheets submitted will be within the ACT.

Cheers

Paul  

Paul Fennell
Editor, COG Annual Bird Report
0407105460

On 8 Apr 2016, at 09:29, David Rees <> wrote:

Folks

I have issues with the interpretation of the Scarlet Robin data set used here.

First the data as presented does show a decline in number of birds seen over time at the points surveyed, however what does this mean?

The data set comes from a wonderful long-term survey of 'woodland' sites with peaks in abundance of this species are seen each year in winter, which is in keeping with most peoples experience of this bird in the Canberra district. 

Many of these birds are likely to be non-breeding birds that have come from somewhere else in the the ACT or from nearby NSW - given that they are not seen/ seen much less at these locations at other times.  Most likely they are from a location of higher altitude, or even somewhere else who knows!.  Such places may, in many cases, be outside the 'woodland survey area', i.e not captured by this data.  

Are we assuming that the reduction seen over time in number of birds seen in winter at locations close to Canberra means that this bird is declining more generally in the region? it appears that we are.  I would be cautious about this.

Winters have got milder in Canberra in the last 15 years and in that time we have had a big drought and a major bush fire event. 

Milder winters may mean birds are not moving to lower altitudes like these used to because they do not have to. Food - e.g. insects remain accessible for longer, and snow cover is less meaning that such food is not covered up. 

The sudden spike in numbers of these birds seen by many of us around Canberra during cold snaps last winter, suggests to me that this could be an issue. 

It may also be that climate change, drought and our major bush fire event of 2003 has given this species a hard lime of late in places where it is now breeding, which may also explain why we are seeing less in winter around the City.  Things may or may not get better over time depending on how these 'large scale'  issues go, things we have little control of on a local level.  

The ACT is fortunate in many ways given that almost all of the highland habitat around here is already National Park or is on 'lightly farmed' rural lease.  Much of the quality lowland foraging places close to the city are already in the 'Canberra Nature Park', though some other areas are still being lost as the city grows.  This seems to me to be a reasonably good deal for this species, given that it could be so much worse given 'development Dollars' are at stake.

  

To get the best handle of this bird I think we need to understand what is happening where they are breeding, not what is happening where they come for winter, as this data set seems largely to do.

Right now I don't think we really know what is going on with this bird on a regional basis. There may be a decline but this excellent data set seems to me to ask more questions than it answers.

Up to us to find out what is actually going on. 

Sincerely

David

www.birdsofAustralia.video

.

On Fri, Apr 8, 2016 at 7:26 AM, Jenny Bounds <> wrote:

Although people do still see quite a few Scarlet Robins around, the COG analysis of its woodland survey data shows that the robin has a significant long-term downward trend.  The COG reports are on the COG website under conservation sub-head; the 10 year analysis report 1998 to 2008 has trend graph and notes on Scarlet Robin (as well as other woodland species).  For some of our woodland species, eg Hooded Robin and Brown Treecreeper which are now scarce in the landscape, the abundance levels are too low for statistical analysis.

 

COG nominated the Scarlet Robin for listing in the ACT and will be putting in comments on the draft Action Plan.

Cheers

Jenny

 

From: Ace Frawley [
Sent: Thursday, 7 April 2016 6:56 PM
To: Cog line <>
Subject: [canberrabirds] Scarlet Robin and Thompson

 

The Scarlet Robin sure is getting a lot of media attention of late, with the draft action plan open for comment.  I see this species a lot in the bush that has now been proposed as a new suburb in Tuggeranong, so that would be more habitat lost.  I can use the same feedback to the ACT Government on both the proposed new suburb and the draft action plan.

 

http://www.abc.net.au/news/2016-04-07/scarlet-robin-facing-extinction-in-canberra/7306650?WT.ac=statenews_act

 

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