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An interesting topic of conversation - though considering I am doing my PhD in mixed-species flocking I may be somewhat biased!
Regarding nomenclature, the terms mixed-feeding flock, mixed-species foraging flock, mixed-species flock, etc are all synonymous, and the observations being made around Canberra at present are quite representative of this rather widespread phenomenon. Morse (actually 1970 - see Martin's link below) describes flocks as "any group of two or more birds, whose formation depends upon positive responses by individuals to members of their own or other species", the mixed-species flocks referring to the 'other species' version. Feeding aggregations are somewhat different - essentially these do not move in space, rather the individuals themselves move in space in response to the food source. Feeding aggregations are most common in frugivorous birds such as large pigeons, etc. In this case, the food resource is the mechanism driving the presence of individuals in close spatial proximity, as opposed to the behaviour of the individuals themselves.
Geoffrey's question of species nuclearity is a particularly good one. Firstly, the question "What is 'a' nuclear species' is still being debated. In the local context, I am hoping to answer this question myself through my present work, I'll be sure to pass on my findings to the list. I note in Geoffrey's latest email that he mentions the effect of territory size vs flock home-range in fairy-wrens - an effect which is reported widely in the neotropics and may well be one of the underlying mechanism determining individual participation by many of the species, whereas others are entirely free of territorial bounds (pardalotes, silvereyes spring to mind).
Happy to answer any questions on- or off-line and keep enjoying those mixed-flocks! (I was lucky to observe some amazonian flocks recently where the species count exceeded 100 in a single flock!).
Damien
Date: Sat, 21 May 2011 17:51:56 +1000 From: To: CC: Subject: Re: [canberrabirds] MFF with a difference - Tallagandra Lanem Sutton Geoffrey According to the version I have accessed http://en.wikipedia.org/wiki/Mixed-species_foraging_flock was last updated on 29 April 2011 so it is possibly not that out of date. Its content is however very dense and I couldn't really make much sense of it. This may be because I am averse to terms such as "Nine-primaried oscines" or possibly because it seemed to be heavily focussed on the tropics.
I wonder whether what we term "mixed feeding flocks " are not more like (quoting from that Wikipedia article) " feeding aggregations, which are congregations of several species of bird at areas of locally high food availability." Googling the "feeding aggregations" term gave little of relevance to this discussion.
I googled ‘’Mixed-species foraging flock’’ and the most commonly cited "scholarly" article was http://www.jstor.org/pss/1942443 from 1969. As with most scholarly articles it is not available to mortals outside the gleaming halls of academe (unless one pays an exorbitant fee) but hopefully the abstract will give the idea.
Martin On Sat, May 21, 2011 at 5:26 PM, Geoffrey Dabb <> wrote:
Good Michael. Speeding vehicles are the bane of roadside birdwatchers on country roads.
We seem to have settled on ‘’MFF’’ in this part of the world. In some places ‘’bird wave’’ is used. There is a Wikipedia article (not updated for some time) under ‘’Mixed-species foraging flock’’. Around Canberra seems to be as good as anywhere to study our woodland/grassland ones. One question is whether a particular flock is mainly feeding or ‘’moving through’’.
Another question is ‘’What is the nuclear species?’’ Steve Wilson used to suggest the YR Thornbill, and that flocks tended to disintegrate when the YRTs broke off to start nesting. I’ve noticed a lot of Buff-rumpeds, so far, with the woodland flocks this year and they certainly contribute to the noise side of things.
From: MJ and ME [
Sent: Saturday, 21 May 2011 4:56 PM
To:
Subject: [canberrabirds] MFF with a difference - Tallagandra Lanem Sutton
G'day,
Went for a drive along Tallagandra Lane this afternoon. At about the halfway point there was a MFF consisting of Diamond Firetails (about 10), Scarlet Robin (2), Australian Pipit (about 20), Yellow-rumped Thornbills (too many to count) and about 10 White-fronted Chats. They were on the edge of the road in tussocks of grass but feeding on the ground. Would have spent ages watching them except a car came along at great speed and scared them all off. Some of the Diamond Firetails were juveniles with black beaks.
Michael Kingsford |
