GANG GANG CENTRAL

[martin butterfield <>]

It would require some heroic assumptions to try to estimate from GBS data,  with any precision, the number of individuals of any species in Canberra at a point in time.  So I am resisting the temptation.  

However, in year 28 Gang-gangs were seen at least once in 32 suburbs of the urbanish parts of Canberra and Queanbeyan.  None of these came the sites  in Gungahlin or Tuggeranong (other than Kambah).  So I suspect that the place Bruce visited is not vacuuming all the Gang-gangs in the ACT.

From my dealing with the species I have frequently found them to be totally unfased by humans when there is a food or water source available.  At Bruce I took photographs from about 4m away as they fed on (from memory) Grevillea seeds while at Carwoola I have watched, from about 10m,  a group of 10 bathing in a small pond.

I suspect that when the owner of the house becomes unable to afford the seed supplies or otherwise is unable to keep up the work the birds that are visiting this site will search around for alternate sources and in so doing meet Gang-gangs from other areas and return to a more normal lifestyle.

Martin

On Sun, May 23, 2010 at 1:47 PM, Geoffrey Dabb <> wrote:

Just some comments on your comments, Bruce.  I’m quite happy for anyone to disagree.

 

First, I do not entirely favour the zero-sum theory that there is a finite number of Gang-gangs around Canberra (say 50), and if they are somewhere else you won’t get any.

 

I would distinguish locally breeding birds from the winter influx.  As to the former, they like high hollows in mature trees, which would limit breeding numbers and, I think, account for the very few local breeders we have preferring the older suburbs of Canberra rather than the more recently planted-up sheep-paddocks.

 

The winter influx creates the apparently large numbers.  As JMF says in BITAHC:  “ flocks come down from the mountains to feed in the trees or shrubs growing in the parks and gardens.  Each year they may be seen feeding in the ornamental pine trees and Pyracantha hedges in the heart of the city”.  This is the reason, perhaps, for the iconic status.

 

From my observations, while they certainly feed in eucs they relish buds and fruit (generally for seed) of exotic and out-of-area plantings.   I no longer get regulars around here since the Cotoneasters were removed.  They occasionally visit a neighbour’s Chinese Pistacio until it is eaten out.  The most regular influx that you can set your calendar by is in a Griffith street planted with Crataegus crus-galli.  In past years I have seen as many as 40 in that street, although this year the most I counted was 11.

 

In short I think the high numbers seen in Canberra are due to (a) out-of-area plantings and (b) feeders.

 

Now, why do some areas not get them?  Perhaps they like a combination of tall mature eucs to roost and loaf in (they like yellowbox) and reliable near-at-hand tucker.  Like other cockatoos they learn where the food sources are (and maybe need to  learn about any new food sources) and use them until they are exhausted.

 

Coming back to zero sum:

 

(a)     If the whole of inner-Canberra was put under high-rises and car parks, would the present influx be diverted to the outer suburbs?  (Possible answer – maybe, but only if food availability and other requirements were similar)

(b)   If all relevant conditions in inner Canberra were duplicated in the outer suburbs would there be a corresponding increase in the GG influx?  (Possible answer -  Surely not.  That would require an increase in breeding numbers which, one would think, are limited by hollows, territories and availability of breeding-season food supply.  Indeed there is a view that overall numbers are decreasing.)

 

     

 

From: Bruce Lindenmayer [
Sent: Sunday, 23 May 2010 12:37 PM
To: 'Canberra Birds'
Subject: [canberrabirds] GANG GANG CENTRAL

 

Last week I visited a private back garden in a southern Canberra suburb, where I was astounded to see some 5 or 6 feeding tables covered in sunflower seeds, with the largest flock of Gang gang Cockatoos I have ever seen in the ACT. There were more than 20 birds along with much smaller numbers of Little Corellas, Sulphur-Cresteds, Crimson Rosellas and King Parrots. The Gang gangs were extremely tame and approachable. Next to the feeding tables were very large bags of seed.

 

The elderly resident claimed that birds had been fed like this for more than 30 years, with up to 43 Gang gangs observed foraging at once. Other parrots were "chased away".

 

There were at least four birds in immature plumage, so one could assume that there are now generations of Gang gang dependent on foraging at that site.

 

I made the obvious point (diplomatically, I hope) that the birds might have some problems when inevitably, they would no longer be able to be fed in this way. However, I  am sure that nothing will change in the short term.

 

Whilst the property in question is several km from Chapman, I now suspect there is a reason why I have never seen a Gang gang here.

 

Given the general scarcity of Gang gangs and their iconic status in the ACT, I think this matter is unfortunate, although I don't know whether there is anything that could be done about it.

 

Other opinions?

 

Cheers,

 

Bruce