birding-aus
>about 12 - 15 Red-necked Stints were accompanied by another bird with VERY
>much paler colouring. All of the other birds (in non-breeding plumage)
>were mid to dark grey above, with quite obvious dark markings on the grey.
>The one pale bird had uniform, slightly mottled, very pale colour above
Is it possible it was a bird in fresh Alternate plumage? Fresh Alternate
(=summer=breeding plumage) has very broad grey or even whitish tips to all
the feathers of the upperparts. It is only after the feathers become worn
that the black centers and rusty edges become apparent. I have seen such RNS
which looked stunningly pale and uniform without a hint of color and very
little trace of black, yet which were already in full Alternate plumage (ie
all the visible feathers were already replaced). To test this idea, you need
to look very closely at the bird. When the wind ruffles the neck feathers
you might see some red coloration showing through. If you look critically at
the pattern of the scapulars, you should be able to see that they are
subtlely different from the Basic feathers of the surrounding birds. In
particular, they will be fresher, since these are unworn Alternate feathers
vs comparatively worn Basic feathers. Also, the pattern is usually
different, even if you can see only the tips.
If you have a copy of "Photographic Guide to the Shorebirds of the World" by
David Rosair and David Cottridge you can see a photo of such a bird on page
147 bottom left hand corner. You can see how pale it looks above, though in
that bird there has already been enough wear to expose some of the red on
the throat and the black spots on the chest. The scapulars of that bird are
a bit hard to read. Clearly some are newer than others, but it looks a bit
to me as if the oldest, brownest most frayed feathers might still be
Alternate feathers - probably just the first to be replaced in the recent
molt and so they have come out with a pattern not very different to Basic.
So essentially, that could be a bird in full, fresh Alternate plumage.
Compare it with the one just above it and you can see the effect of a few
months of wear!
Chris Corben
PO Box 2323
Rohnert Park
CA 94927-2323
USA
707-584-8711
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