Over the past three to four months, I've been watching the local flock of Gang Gangs. Originally, in February, there was only 3 of them, and I assumed it was a family group. However, that group has been growing larger (they fly past my window nearly every day), growing to five and then ten, and now 15.
I don't know much about parrot behaviour, but why are they gathering into such a large group? Is it just a feeding flock for winter, and will they disperse again in spring? There's also a massive mixed flock of corellas and cockatoos around (it was massive in late summer, and has only been getting bigger), and recently I've seen a couple of large flocks of King Parrots and Crimson Rosellas. As this is central Canberra, I'd have thought they would have dispersed towards the coast for winter rather than staying here?
I do have an uneducated theory on this. As i see GG's all year here i am thinking that maybe the ones that live in Canberra in Summer go to the coast for Winter and the ones that live in the mountains come to Canberra for the Winter.
Are you taking part in the GG survey conducted by COG? If not i am sure they would like to here from you.
http://canberrabirds.org.au/observing-birds/gang-gang-survey/
Shorty......Canon gear
Canberra
http://www.flickr.com/photos/rawshorty/
There's been a similar discussion in this section, about large flocks of Yellow-tailed BC's - perhaps it's common with many Cockatoos/Parrots to merge their family groups together, outside of breeding season?
The Habitat, Seasonal Movement and Feeding sections of this might answer a little bit of some of your questions too
http://www.birdsinbackyards.net/species/Callocephalon-fimbriatum
West Coast Tasmania
I had a look at the discussion about YTBCs, and it seemed that your conclusion was that there was so many of them together because there was a secure source of food in the pine trees. With all the other cockatoos aound, I couldn't see what the advantage was foodwise- they disperse and come back to roost, yet the group of Gang Gangs stays together. Surely there wouldn't be much food around that the white cockies aren't eating?
The BiBy factsheet sorta answers my question (but not quite): that they go from the highlands to the lowlands, which is also what my birdbook says. I just thought that as they were here in summer, Canberra must be the highlands, so why are they here in winter? Shorty's theory looks reasonable, as I guess there isn't much native vegetaion in the sections of the Molongolo and Shoalhaven valleys they'd have to cross to support them.
Well no, I don't believe that was my conclusion at all.
Platypus wondered why there were larger than normal flocks flying above their property. The information I read & mentioned about Yellow-tails was that small family groups join together outside of breeding season & move towards the coast in winter, from elevated areas to lower lying areas. So that could explain the larger than normal flocks flying over their property.
The food source is both relevant and irrelevant in some ways, in regards to the large flocks. Naturally, the larger flocks are going to fly towards a known food source, that goes without saying, that's relevant of course. But the pine plantations, for example, are hundreds and hundreds of acres. Yet, rather than break up into their small family only groups again once they all get there, and spread out all over the plantation into their own little areas, they choose to continue to flock together in a large group. So the food source is irrelevant in that respect I think, as far as staying in a large flock. I don't have the answer as to why they do it, just read that it is what they do outside of breeding season. Perhaps it's their AGM?
So my answer was just really in relation to you wondering why "they gathering into such a large group? Is it just a feeding flock for winter, and will they disperse again in spring?", so sorry for any misunderstanding there
.
As far as availability of food and competition for it, and the fact they're still in Canberra, no idea - I think Shorty is probably on the money with his direction of thought/observation though!
West Coast Tasmania
In Autumn the gang Gangs come to my place for the Hawthorne berries (Haws). There is usually a group of about 15 birds, they only stay for about 3 weeks. I think they have migration routes they follow to take advantage of food sources.
Ah, Greg, no doubt those Gang Gang Cockatoos are intelligent enough to wrap their droppings in paper & deposit them in a rubbish bin so that they won't cause Hawthorns to regenerate in natural bushland.
Hawthorns aren't a big problem here, only a few grow near the creek, I think it is ok if it means I get Gang Gangs here.
except for the 6 month period from Mar - Sep '13 when I was in Canberra
Peter
I only saw them on QLD weekends at that time
Shorty......Canon gear
Canberra
http://www.flickr.com/photos/rawshorty/