Re: FW: FW: [canberrabirds] Red-rumped Parrot abundance

[David Rees <>]

some footage of some at the end of my driveway filmed a couple of years ago 

https://vimeo.com/137430175

On Thu, Jun 8, 2017 at 1:16 PM, Con Boekel <> wrote:

For some years I have part of the COG Annual Report team. Each team member does the write up of pretty well the same particular set of species every year.

The Red-rumped Parrot is not one of my 'babies' so I will refrain from discussing it specifically.

For me the most interesting moment in writing up a species for the Annual Report is to compare and contrast the Woodland Survey, GBS and General Records graphs.

I write to raise the point that there are recent very large changes in recording and reporting effort which is, IMO, having a significant impact on the General records. For many species there has been an astonishing increase in data for some species in recent years which I put down to the ease with which anyone with a phone can record stuff once and simultaneously send it to an electronic database, and to do so with marked ease.  My view is that what we are getting now is not more data of the same sort that we used to get in the General records. Without wanting to get into the particulars, it is obvious that the new surge of data is not only much larger in quantity, it is different. It follows that the difference in data effort and reporting may cause a statistical effect independent of what is really happening to a species.

regards

Con

On 6/8/2017 11:57 AM, Geoffrey Dabb wrote:

Thank you John.  Once again the particular is the enemy of (in this case a crude) generalisation.

 

They certainly feed on more closely mown grass provided there are emergent seed heads.  In the below selection of feeding snaps the upper left shows a parrot feeding on small seeds on the mown lawn of Commonwealth Park.  Another feeding technique is the use of fence wires, stouter stems or even tree trunks (middle pic) to access taller seed heads.  

 

 

From: calyptorhynchus . [m("gmail.com","calyptorhynchus");" target="_blank">com]
Sent: Thursday, 8 June 2017 7:17 AM
To: Canberra Birds
Subject: Re: FW: [canberrabirds] Red-rumped Parrot abundance

 

Not sure about "rough-mown" areas, my observation is that RRPs like extremely short grass, where they seem to feed on seeds from plantago and various daisy spp.

On Hughes Oval (my main stamping ground these days) flocks sit in trees twittering with impatience on frosty mornings... guess they have to wait for the frost to melt before they can feed.

John L

 

On 7 June 2017 at 18:45, Geoffrey Dabb <> wrote:

Perceptions about this sort of thing are always interesting.  While the accumulated statistics are of great value, I think some caution is needed in interpreting them.  I would not myself regard the RRP as a ‘garden bird’.  However it feeds on seeds (mainly grasses and forbs) in open areas, including nature strips.  The garden bird survey can include parts of nature reserves, playing fields, median strips etc so I would think the GBS over time is likely to reflect the character, over time, of the 3ha ‘garden sites’ included in it.   

 

In the 2016 GBS report the RRP has an ‘abundance’ (numbers related) rank of 34.  A comparison with some other species is below.  As a matter of interest I have added the F% (percentage of GBS sites where recorded in the course of a full year).

 

11.  A King-Parrot (92.2)

17. Eastern Rosella (96.9)

20. Little Corella (75)

26. Gang-gang Cockatoo (60.9)

32. Rainbow Lorikeet (40.6

34. RRP (53.1)

35. YTBC (68.8)

42. Superb Parrot (31.3)

 

The general statistics should be more relevant to this species.  In 2016 the RRP had a rank of 21 in ‘total records’. This is in front of the King-Parrot, for example, possibly due to seasonality factors.

 

While the CBN general table excludes GBS data, it seems that GBS data is included in the BirdInfo PDFs (perhaps contrary to the statement in the heading). This would be significant as the total number of weekly GBS sheets is considerable.  Anyway, two of the graphs are below.  Note that they end in 2013.

 

 

 

One point about the general statistics is that apart from the GBS data (if included) a large component is collected by a relatively few industrious observers, so certain areas might be  disproportionately represented.

 

Now, turning to general impressions my own is that, yes, there have been noticeably more RRPs about in areas I visit over the last couple of years.  This is especially so in the post-breeding period after families leave the woodlands and sometimes coalesce.  This might be due to the birds having learned to make more use of rough-mown areas around Canberra, which might offer more food because of recent weather patterns.  One way or other, I would think their presence is food-related.

 

Very happy to be corrected if I have anything wrong. .

 

 

 

From: Duncan McCaskill [m("gmail.com","duncan.mccaskill");" target="_blank">mailto:duncan.mccaskill@gmail.com]
Sent: Wednesday, 7 June 2017 10:37 AM
To: Philip Veerman
Cc: Canberra Birds
Subject: Re: [canberrabirds] Red-rumped Parrot abundance

 

For Red-rumped Parrot, the reporting rate and the abundance measure closely track each other. The abundance measure looks noisier - for example in 2004/05 there were a few records of large flocks at one site, giving a large peak in the graph below.  The average group size has hovered around 5 for most of the survey, with lows around 3.5 in the mid 90s, highs around 5.8 in 1984/85 and 30 years later in 2015/16. The peak of 9.4 in 2004/05 is probably an outlier.

 

 

​ Duncan.

 

On 6 June 2017 at 22:34, Philip Veerman <> wrote:

Actually the abundance statistic from the GBS is the “A” value, the one that has traditionally been used for the GBS graphs in the COG ABR and used in The GBS Reports and BOCG. The R value is, as Duncan indicates, merely the Reporting rate, and has rarely been given prominence in COG information. It is the proportion (in this case %) of observer weeks, at which the species was recorded. This is not abundance, it in no way uses the available information as to the numbers of birds observed. Although there is an obscure connection between the two statistics. If group size was always a constant (such as always one, which it clearly isn’t), then there is a direct connection. The GBS Report explores this connection, as a highlight of the GBS.

 

Philip

 

From: Duncan McCaskill [mailto:m("gmail.com","duncan.mccaskill");" target="_blank">duncan.mccaskill@gmail.com]
Sent: Tuesday, 6 June, 2017 7:52 PM
To: calyptorhynchus .
Cc: Canberra Birds
Subject: Re: [canberrabirds] Red-rumped Parrot abundance

 

Summaries of COG's data for each species are available on the COG website under Our Birds / Bird Info. The Red-rumped Parrot summary sheet is here: http://canberrabirds.org.au/wp-content/uploads/2015/02/Red-rumped-Parrot.pdf (PDF download).

 

This graph of the reporting rate from COG's Garden Bird Survey shows a decline to about 2002, followed by an increase back to 1980s levels. 

 

 

 

Duncan McCaskill

Coordinator, Garden Bird Survey.
​

 

On 6 June 2017 at 17:16, calyptorhynchus . <> wrote:

Do the COG databases and other collections support my idea that RRPs have become more common over the past 20 years in Canberra?

--

John Leonard

 

 

--

John Leonard
Canberra
Australia
www.jleonard.net

I want to be with the 9,999 other things.