Hi Everyone,
> Interesting that people tend only to think of confusing Whiskered
> with White-winged Black without realizing that some can confuse
> the Black-naped in there as well. It also shows the fallibility of
> relying on single-feature identification.
May I endorse Niven's comments? I spoke about terns recently at a Birds Qld
meeting, and apart from the obvious content, I tried to convey the idea: be
careful. I am out there with terns all the time, and I am cautious. The more
I learn, the more cautious I become. My experience is limited to Caloundra,
SEQld.
Observers looking to separate the Whiskered and White-winged Black from the
Black-naped Tern need look no further than the tails. Both the "marsh" terns
(Whiskered and White-winged Black) have short, stubby tails, like martins,
whereas the Black-naped has a longer, swallow-like tail.
It has also been suggested that some of the sightings of Black-naped Terns
in SEQld may in fact be Gull-billed Terns, to throw in another distraction.
When it comes to separating the Whiskered and the White-winged Black, it can
be a bit more subtle. I am very inexperienced with Whiskered Terns. However,
in non-breeding plumage the White-winged Black is the only local tern with
the side appearance of wearing ear muffs. This is because there is a very
high white patch which cuts high into the rear crown cap, a bit like
high-cut bikini knickers. Have a look on P229 of Pizzey on the juv and
non-breeder White-wing, and burn that white patch into your memory bank. It
doesn't happen with any other tern locally.
Tern moult is rather complex, and from week to week the appearance (most
obviously the caps) of species will change. This occurs particularly during
the summer when the trans-equatorial migrants are here. Therefore I have
every sympathy with the illustrators of field guides, who cannot hope to
convey all the subtleties.
Cheers,
Jill
--
Jill Dening
Sunshine Coast, Qld
26º 51' 152º 56'
Ph (07) 5494 0994
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