I don't know if this is the best place to go into all this, but .... The
generalisation in HANZAB is : "All woodswallows roost communally, often
huddling together side by side on branches, or clustering together on a
surface such as a tree-trunk."
The entry for the White-breasted says "Do not cluster in the manner of other
woodswallows .." [citing inter alia the Chapman Wingspan article] However,
they are said to "LOAF" side by side on a perch etc. Masked: 'said to
cluster at night ... occasionally cluster during day, usually in windy and
inclement weather ....' White-browed: [won't quote] clusters at night,
sometimes during day when windy. Black-faced : roost in clusters with each
bird closely pressed against neighbour [many records]. Dusky: usually
roost in a cluster. Little: roost 'normally huddling close together in a
cluster'.
So the possible exception is the White-breasted, Steve's claim for
clustering not distinguishing this from perching close together in a line on
thin branch or power line, a commonly seen behaviour with this species.
-----Original Message-----
From: Philip Veerman
Sent: Monday, 23 June 2014 12:43 PM
To: 'William Stephinson'; 'canberrabirds chatline'
Subject: of interest? Woodswallows clustering
Yes I guess it is of interest. We people like to make sometimes arbitrary
definitions of phenomena. My recollection of this issue was that this form
of "clustering" only refers to mass roosting (overnight) of these birds, in
a way that they are basically huddled on top of each other, as shown in the
Black-faced Woodswallows photo. I recall that roosting parallel along a
branch in close contact, as White-breasted Woodswallows so often do in the
daytime, does not count in that definition. Good that Steve shrinks his
photos he says each one was night time, but either way (White-breasted w/s
clustered p.m. along branch) looks like normal daytime perching, (hardly odd
that they might do the same at night), rather than this type of clustering.
So I suspect Graeme is still correct.
Philip
-----Original Message-----
From: William Stephinson
Sent: Monday, 23 June 2014 12:24 PM
To: canberrabirds chatline
Subject: of interest?
Some years ago when away "looking for the night parrot" with Graeme
Chapman (!!!!),
Graeme said only 3 of our wood swallow sp. clustered when roosting. What say
you Mark C?
The attached show 3 that I think have roosted o/night
1 - Little w/swallows clustered in hollow tree p.m. - early a.m. photo
as flying out .
2 - Black-faced w/s clustered p.m. under branches - photo G.C. - tree
now bulldozed, Yowah opal mines.
3 - White-breasted w/s clustered p.m. along branch.
I note that M. Morcombe in field guide says that Dusky w/s cluster at night.
Any thoughts welcome.
Steve.
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