Tom Tarrant 2/4/03 3:46 PM
> Looked to me like non-breeding White-winged (C. leucoptera) but could
> have been n-b Whiskered (C. hybrida).... should White-winged be in
> breeding-plumage yet?
> Some showed dark primary-shaft feathers and some had large black patches
> on rear of head/ top of neck, and there were a couple that appeared to
> be moulting darker feathers. Would welcome any opinions on their identity.
Hi Tom,
White-winged Black Terns (WWTE) are around in big numbers at the moment,
gathering for the northward migration. I have not seen any yet with anything
more than the odd trace of black blotch, but it's a week since I was out,
and things change fast with WWTE. Heavy black on the cap has been present
all summer in young birds, it's a bit like a heavy mohawk haircut down the
neck nape. Adults should have little head colour, but it can change at any
time now. I haven't seen any change in the underwing yet, but certainly the
darkness on the outer primaries from underneath is consistent. I am going
out tomorrow, weather willing (we're up to 250mm, 10" of rain this week),
and will let you know the state of plumage here (for list members, Tom and I
are about an hour's drive apart, and he is inland, whereas I refer to the
coast).
WWTE have me fascinated and puzzled. They are known as "marsh terns", and
stomach contents analysis has shown a strong content of insects. However,
whenever I see them (and I seem to be the only person on this list who sees
them in big numbers, up to 3500 - yes?, any offers?) they behave like
sea-terns. I have watched them through the scope taking food from the
surface of the ocean beyond the breakers, and considered that there must
surely be insects on the surface of the sea, but always rather inclined to
believe that they were actually fishing. Last week I took my opportunity to
go out with the Caloundra Coastguard, to see terns fishing. I watched -
several times - schools of mackerel working areas for prey fish. Terns
gathered overhead, including WWTE, and I watched them diving and taking food
from the surface in the middle of this melee. The men on board explained
that the mackerel feeding habit is to snap at prey, and that bits and pieces
of broken fish float around and that the terns would be taking these pieces
opportunistically. I was so busy trying to stand up in the swell, that I was
unable to lock my binos on a single bird bringing up food, but it sure
looked like the scenario they were describing. I certainly saw terns, both
Commons and WWTE, working the mellee and flying up with something in their
bills. So I am now satisfied that WWTE are taking fish, but whether whole or
broken I can't really say. I just wish the sea would sit still. Little Terns
were also involved in the melees, but I can't say I saw Littles taking
scraps of fish - they just seemed to be flying around, and many of them were
fishing individually and apart in their usual manner. (by this I mean they
would fly around watching the surface, see a small fish, and dive for it).
Cheers,
Jill
--
Jill Dening
Sunshine Coast, Qld
26º 51' 152º 56'
Ph (07) 5494 0994
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