Red-rumped Parrot abundance

[Jack & Andrea Holland <>]

I have followed this discussion with interest, especially Geoffrey’s contribution below, as I agree that the abundance of this species may not be fully captured by either the GBS or general COG surveys.

 

Paying more attention from early 2016 to roost flights in Chapman/Rivett/Duffy I had been seeing intermittently in this area since early 2005, as well as finding 4 roost sites within 500 m of my GBS, has demonstrated that for most of that year (including through the breeding season) there were at least 75 birds (a very conservative estimate) roosting/flying through this area.  In 2017 this number at least doubled for March to May (again a very conservative estimate), including in one of the flyways that slightly changed direction.  During this time the maximum number of birds I counted during regular surveys of Cooleman Ridge and Narrabundah Hill in the direction to where they fly was 10.

 

At the same time Jean Casburn has had up to 50 roosting in her GBS site only 500 m from the major Rivett/Chapman flyway at its closest point.  Even more important is that Megan Mears/Michael Lenz have been counting up to 220 birds coming in to roost in Watson this year, but I understand with a nearby GBS site hardly ever recording Red-rumped Parrots, similar to my experience in 2016. 

 

I’m sure our experience is replicated in other areas of Canberra, and to me this underlines the value of roosts and roost flyways in estimating the abundance of (the many) species that undertake these flights and roost colonially.

 

I have mentioned the above a number of times in my Gang-gang column and am just finishing writing it up for CBN.

 

Jack Holland

 

From: calyptorhynchus .

Sent: Thursday, June 8, 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 [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: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.