Subject: mystery drawing
Date: Sep 10 15:08:47 1997
From: Dennis Paulson - dpaulson at ups.edu


Hi tweeters,

Here is a copy of my comments on the drawing I posted a week or so ago.
Michael Price already responded to some of the ideas that were put forward.
Remember, *no one* knows what species this bird was. All ideas are
speculation, as the bird is long gone and wasn't photographed. Without a
photograph, bird-record committees can only *try* to be objective in
judging a written description and sketch; they don't necessarily have to
succeed.

A bird can be (a) correctly identified and well described, (b) correctly
identified but poorly described, (c) incorrectly identified but well
described, or (d) incorrectly identified *and* poorly described. Birds in
category (a) typically make the cut, and birds in (c) probably often do,
unfortunately, but it is that category that we try to be most vigilant
about. Sadly, (b) also doesn't make it, and no one should be surprised
about (d).

The bird in question (Ruff, St. Charles Co., MO, 6 Aug 95) seems at first
glance to be unquestionably a Ruff. However, on further examination of the
drawing and the meager description, I find I can't endorse the identification.

1. SIZE - "slightly larger than Pectoral" doesn't fit at all for a male
Ruff, which is over 2x the weight of a male Pectoral, same magnitude as the
difference between the two yellowlegs. Female maybe, but not a male, and
the bird would have to be a male to have black on the underparts. Females
rarely do have some black on the breast, but they are rare enough so that
some principle of parsimony would seem to apply here. And you couldn't have
a combination of "remnants of ruff" and smallish size. As there were
Pectorals present, and thus the size should have been correctly estimated,
this seems especially critical.

2. SUPERCILIUM - I don't think Ruffs in any plumage have a supercilium as
well marked as the drawing shows.

3. LORES - Ruffs don't have entirely dark lores; a rather plain-faced look
is typical, with only a smudge on the lores.

4. PRIMARY PROJECTION - adult Ruffs have a virtually nonexistent primary
projection, while the drawing shows what seems to be a fairly long
projection.

[Note I didn't comment about the tail being longer than the wings in the
drawing; this was in part because I didn't think any bird looking at all
like the drawing should have that characteristic, thus I thought it was in
error--which of course means other aspects of the drawing could have been
in error, too.]

What the bird actually looks like is a Pectoral Sandpiper with--for some
reason--a lot of black on the breast. This could happen from oiling,
possibly from some other cause (could the limping be at all related to
this--maybe a damaged area with black feather bases showing?). Nothing
about the described flight pattern eliminates Pectoral (although it could
have), behavior is fine for Pectoral as well as Ruff (although many Ruffs
feed more actively than this bird), bare-part colors ditto (most Pectorals
have a paler base to the bill, but so do some Ruffs). I don't know what to
make of "neck and upper breast mottled and spotty;" this doesn't sound
exactly like Pectoral, but it's not the most explicit description, either.
An adult Pectoral in fall could probably be so described. If a Pectoral, it
would presumably have to be an adult, at that date, and fall adults are
fairly dull, not usually with a "reddish brown" crown, so this is a bit
discrepant from Pectoral also.

I suppose the bird could have been a Ruff that wasn't particularly well
described, but the size discrepancy seems to rule strongly against that
conclusion.

Were any of the observers very experienced? If not, mass delusion can
prevail ("MANY" observers independently identified it). Is this the only
description out of those masses of observers?

Oh, for a photograph! I've had to say that about all too many descriptions
of rare birds.

Dennis Paulson, Director phone 253-756-3798
Slater Museum of Natural History fax 253-756-3352
University of Puget Sound e-mail dpaulson at ups.edu
Tacoma, WA 98416
http://www.ups.edu/biology/museum/museum.html