Hi Tweeters

Mike Smith wrote:

(snip)
>Have we ruled out the earlier thoughts on alternate I plumage? I didn't see
>anything in my books, but my library is limited. I know it sounds weird,
>but what makes sense is two birds, one in adult alternate plumage, one in
>1st-year plumage, both conspiring to confuse us. Anyone have any better
>references regarding Sharp-tailed plumages?

I'm looking at a photograph taken by B. Chudleigh of a Sharp-tailed
Sandpiper (SHSA)in what the caption says is "Adult, breeding plumage;". It's
on p. 328 of The Shorebirds of Australia by John Douglas Pringle (Angus &
Robertson, 1987). It is extensively marked from chin to undertail coverts
with conspicuous dark grey spots, streaks, and chevrons, with large chevrons
particularly conspicuous on the flanks. Pale rufous spotting among the dark
grey streaks and spots of the upper chest impart the impression of a faint
warm rusty--not buff--suffusion starting at the base of the throat and
extending to mid-breast. Its supercilium is subdued and narrow, white marked
by fine dark grey streaks; more obvious is a rusty auricular patch. There is
no sign of a broad, unmarked white supercilium with post-ocular widening.
The forecrown is greyish-white, mid- and rear-crown warm chestnut distinctly
streaked dark grey. The white eye-ring is very obvious, the narrow lores
dark reddish-brown. The back and wing feathers, including the tertials, are
mostly dark grey or black, narrowly fringed white or pale grey, but some
feathers of the mantle seem to be warmer, appearing browner.

My hunch is that this is actually a bird in pre-Alternate molt. The
photograph as taken in February 1984. What strikes me is that the bird is
quite advanced into its Definitive Alternate plumage so early in the year,
being very heavily patterned on the underparts; such a plumage will be quite
worn by July, perhaps suggesting either an Alt 1 or a pre-Basic plumage. But
then, as Western Sandpipers' Def Alt plumages wear, the markings become more
conspicuous, not less, and the birds don't become drabber until a
significant number of grey Basic feathers molt in.

I'm curious about one thing, and I'm apprehensive about asking for fear that
the observers may misconstrue my curiosity as second-guessing, which it most
emphatically is not. I really want to know so I'm gonna ask anyway. Did any
observer of this bird do a point-by-point comparison with the known features
of Pectoral Sandpiper (PESA) at the bright extreme of that species'
Alternate plumage? Just to be suspenders *and* belt, how were this/these
bird(s) be separated from a small, PESA in brighter-than-usual Alternate
plumage?

Reason I ask is that a few years ago we had a *deluge* of northbound PESA
here in Vancouver BC: playing fields, pastures, settling ponds, city park
lawns, just crazy. A few of these birds were so bright as to cause
disbelieving double-takes among a lot of Vancouver's best birders (I'll make
that rank some day, when I stop double-taking on starlings and sparrows ;-)
Well, no surprise, we're not used to seeing them in definitive plumage, the
southbound adults are usually well into pre-basic molt when they hit
Vancouver, and we're pretty familiar with the juvs.

What amazed me, beyond the usual size variation, was the individual range of
intensity of plumage, from standard-issue pale brown to rich chestnuts,
crisp black streakings and feather centerings, and rufous or buff washes
with a complete range of density and amount of breast streaking from heavy
dark streaking with a distinct pectoral division to almost nothing but a
warm buff or pale rufous wash across the breast. Some had indistinct side
streaks, others not at all. You could say there was a certain amount of
double-taking done at Iona Is. that day. I thought then that if anything but
a juvenile SHSA ever showed up here, it had better be in textbook Def Alt,
'cause otherwise, how are ya ever gonna know?

So if the Crockett L. observers saw features that eliminate PESA at the hot
end of their plumage coloration, I want to know what they are, so the next
time a big slug of Alternate PESA hits Vancouver BC, I'll be ready for that
Sharp-tailed Sandpiper hiding in the flock.

Michael Price
Vancouver BC Canada
michael_price at mindlink.bc.ca