The issue of how often to record recurring sightings of the same individual bird of a species, and how these records could be interpreted is an interesting question, and one that regularly exercises the minds and judgement of the ABR report writers and editors.
With respect to the counting and reporting of Aust Spotted Crakes, there has been quite an irruption of the species in the year of 1/7/2012 to 30/6/2013, the ABR Bird year 2013.
The species has been seen in many more sites than previously; mainly it would appear, because there are more suburban manmade sites for them to live in, and observers to see them do it. Nevertheless the birds are there, and are counted, often over and over.
Below is a summary of the sightings, and the relevant draft extract from the soon to be published 2013 Annual Bird Report. With a number of species where there are multiple reports of one or two birds, so there could be a short statement added to the passage to below to indicate this.
What do people think?
Location | |
Birrigai @ Tidbinbilla | 1 |
Bonner Pond 2 Cnr Horse Park Dr and Mulligans Flat Rd | 1 |
Crace Wetlands & surrounds | 17 |
Dickson Wetlands | 12 |
Forde wetlands | 7 |
Goulburn Wetlands | 1 |
Kelly's Swamp, Fyshwick | 57 |
Molonglo River Low-level Crossing Carwoola | 1 |
Mulligans Flat | 1 |
Namadgi Visitors Centre(J19) | 5 |
Parkwood Horse Paddock Pond Eastside() | 2 |
West Belconnen Pond(I11) | 16 |
Australian Spotted Crake Porzana fluminea 272 Rare, Breeding Resident
Another furtive species, now seen in a variety of wetlands in and around Canberra.
General: 121 records is a very high reporting level; it is more than 13x the previous 10YA (9.1) and more than 24x the 30YA (5). Apart from a previous peak recording year of 27 in 2006-07, the number of records from previous years has been between 0 and 18. As expected, many records came from Kellys Swamp (47%), but there were also many records from other local wetlands including WBPD GrI11, Parkwood GrH12, Crace Wetlands GrK11, Forde Wetlands GrL11, Bonner Pond GrL10, Mulligans Flat GrL10, Dickson Wetlands GrK11, as well as several rural sites including Birrigai GrH17, Namadgi Visitors Centre GrJ19, Carwoola GrR16 (BiJ1), and Goulburn Wetlands GrZ01. Records were generally of 1 or 2 birds (mean of 1.9, median and mode both 1), but with numbers ranging up to 9 from Kellys Swamp. The majority of records were from summer (79%) with fewer in autumn (12%), spring (6%) and winter (3%). No breeding recorded.
Cheers
Paul
Paul Fennell
Editor Annual Bird Report
COG Databases Manager
026254 1804
0407105460
From: John Harris [
Sent: Saturday, 5 April 2014 11:50 AM
To: Jenny Smits; 'Canberra Birds'
Subject: Re: [canberrabirds] Gang Gang and COG survey question
I have seen no Gang-Gangs in Gungahlin but I am interested in the answer to Jenny’s question because I have always found this a difficult ‘ethical’ question regarding repeated sightings generally.
I have been reporting one or both of a pair of Spotted Crakes in the little Crace wetland virtually every week for well over a year now. It is clear they are the same two birds. Not long ago I noticed Geoffrey Dabb used the phrase ‘now common’ with regard to SC. I know Geoffrey can access other records than mine but it did make me wonder if my reporting helped give an impression that SCs are common. Similarly, I could have reported the breeding of a Musk Duck (singular) in Yerrabi Pond every day for a month if I wished (I didn’t) but how many breeding records is that? I reported it a few times. What if other Gungahlin members reported the same breeding event regularly?. Are Crakes, for example, becoming more common or is the increase in observers the real factor? It does make me wonder how often the same birds get reported and how this influences any calculation of their frequency.
Family of three gang gangs in my liquid amber as I write.
Could I clarify something for the COG Gang Gang Survey – I see gang gangs nearly every day in Deakin. They are often in my liquid amber this time of year, across the road at my bosses (Stonehaven Cres) or at La Trobe Park, Deakin. My sightings are only incidental and are generally the same family group of 3.
I wonder whether it is important to the COG survey to enter each sighting everyday even though it is the same group, in the same place, feeding on the same forage? I guess it depends on the question the survey is trying to ask…
Thanks in advance
Jenny Smits
From: Mark Clayton [m("bigpond.com","chollop7");">]
Sent: Saturday, 5 April 2014 10:37 AM
To: 'calyptorhynchus .'; 'Canberra Birds'
Subject: RE: [canberrabirds] Lorikeets in Hughes (and Gang-Gangs)
Hi John,
I think point number 2 covers what happens when it is wet. I can’t see where Gang-gangs would go in wet weather as the whole area was pretty wet in that period.
With the Rainbow Lorikeets in my area (Kaleen), yesterday I had two feeding in the rain in the tree in my front yard where I reported 5 birds a week or so ago. I am yet to be convinced that the birds we see locally are anything other than aviary escapees and email conversations with several people tend to agree with me. Despite the rain I stood under the tree and watched them for about 10 minutes – sorry, no Gang-gangs but I am waiting for them to arrive in a neighbour’s yard where they fed in a Hawthorn last year.
Cheers,
Mark
From: calyptorhynchus . [m("gmail.com","calyptorhynchus");">]
Sent: Saturday, 5 April 2014 9:47 AM
To: Canberra Birds
Subject: [canberrabirds] Lorikeets in Hughes (and Gang-Gangs)
A flock of eight Rainbow Lorikeets screeching past in Hughes this morning.
No Gang-Gangs in Hughes since the 24 March (when the rain started). I had seen or heard them almost daily since the beginning of the year till then.
When people have entered all their Gang-Gang data at the COG/ALA site it will be interesting to see if all GG records in the ACT ceased in this wet weather. If they did it could either be because:
1. GGs leave Canberra in wet weather
2. Observers don't get out and GGs are less vocal/obvious in wet weather.
Or a combination of 1 and 2.
--
John Leonard
