Much as it hurts to do so, I have to admit a glaring mistake.

When I found my "life" Bristle-thighed Curlew at Ocean Shores on 23 May, I
was about as excited as a birder can get. The bird flew in calling, landed
right in front of me, and had me hopping up and down with excitement. About
20 meters behind it I saw another curlew, which, with a quick pass by the
binoculars, I considered a Whimbrel, as it looked duller and paler beneath
and rather heavily barred on the flanks. It never called, although the
first bird vocalized frequently.

As I watched the first bird, trying to get closer to it for photos, the
second bird moved up near the first one, and I was elated that I could get
comparative photos of the two species. I concentrated on the BTCU and
really didn't look closely at the other bird, knowing my photos would
capture it and being convinced it was a Whimbrel. The two birds then
separated, and I advanced slowly on the BTCU, finally getting somewhat
better photos, although still distant. All of a sudden the second bird flew
and the first bird followed it; I tried to get a few shots in flight.

I just got the slides back last night, as I finished the roll recently. To
make a long story short and embarrassing, as each slide appeared on the
screen I thought to myself "oh oh, that second bird sure looks a lot like
the first one," and by the time the slide of the birds in flight appeared
(I caught both of them in poor focus in flight, although I didn't recall
even seeing the first bird fly), I was unsurprised to see that both had
bright buffy rumps.

I had been hoist by my own petard, if that's the appropriate metaphor. I
spend a lot of time when teaching about birds exhorting people to "look at
every bird closely." That's one of my main messages, and I lost it
completely when this cosmic bird appeared. I made a snap decision about the
second bird and really paid it very little attention thereafter, except to
note in my mind how it differed from the "obvious" BTCU.

I was much more intent on getting good photos than on documenting the
record carefully, as the coast was so inundated with BTCUs that I knew my
sighting would be accepted with little doubt and that the best
documentation would be photos that could be compared at some time in the
future, perhaps allowing us to determine how many birds there were.

I've put a few photos on display at

www.ups.edu/biology/museum/BTCUphoto.html

In the photos, the differences in plumage are minor. The second bird (on
the left) has more heavily barred flanks (but not the rear part of the
flanks and the undertail, which should have alerted me immediately), and it
was so pale underneath as to look off-white. The first bird wasn't very
bright below, but it was obviously buffy, while I saw no buffy on the
"Whimbrel." In the slides, however, the birds look virtually identical,
especially in the vivid back pattern which of course is diagnostic of BTCU.
I should add that my wife, who was watching them in the scope, kept saying
to me, "I'm not sure I can figure out which bird is which." I should have
recalled the saying "Out of the mouths of babes . . . " and looked again.

My making this momentous goof was probably a combination of excitement, the
"I wouldn't have seen it if I hadn't believed it" syndrome (which I've
critically applied to all too many observations of rarities by other
birders), and a relaxation of standards brought about by minimal attention
to birding in recent years. None of these is a good enough excuse; I
apologize to my colleagues.

Now that the hard part is over, there is something to be salvaged.

It seems likely that at least 3 birds visited Ocean Shores, probably 5 if
the birds that Bob Sundstrom and Hal Opperman first saw there were
different. Was the single bird seen repeatedly before and after at Westport
and Ocean Shores different from my pair? Could there have been as many as
6-7? I guess we'll never know for sure, especially as none of the others
was photographed except for the one by Patrick Sullivan. It is a
black-billed bird and looks much like my black-billed bird, but I could be
convinced they were different birds, after comparing the photos on the web.

The most important message is to ignore my comments to the effect that "the
two birds looked amazingly alike." I guess that's not too surprising, as
they were the same species. I still think the two species are very similar,
but I can't use my own experience in the field to back that up now! The
difference in dorsal pattern in adults of the two species is very obvious
and, I think, still the best field mark to distinguish the adults.

The comments I made on differences in bills between the BTCU and the "WHIM"
obviously must be ignored. Interestingly then, these differences were
between 2 BTCUs. One bird had an all black, rather sharply angled, slender
bill, the other a pink-based, less angled and heavier bill. All this is
evident on the rather distant photos I obtained, the two birds brought
closer together by the magic of Photoshop.

Now that my birds are correctly identified, it's interesting to compare
them with the two birds that had spent so much time at the South Jetty, as
those birds disappeared from Oregon a day before my birds appeared at Ocean
Shores. However, the differences in their bills don't match. Of the SJCR
birds, the one with a pink-based bill had a thicker and longer bill than
the black-billed bird (at least from Ruth Sullivan's very close photos),
and the curvature seems similar in the two, while in the Ocean Shores
birds, the pink-billed bird's bill is shorter, less curved, and only a
little thicker.. Could the SJCR birds have been an adult male and an
immature female, the Ocean Shores birds an immature male and adult female?

I can't imagine that BTCUs change bill *shape* as well as color during the
year, but when I looked at the images of all the birds photographed along
the west coast, it struck me that all those with all-black bills had
slender bills, while all those with pink-based bills had thicker bills.
What's going on here? This is a really interesting phenomenon!

Another note: I mentioned something about a possible hybrid BTCU x WHIM
that I had examined. I've reexamined the photos of that specimens and my
notes, and the bird looks pretty much like at BTCU but has the pale color
on the tail pale brown with buff tinges, and heavy brown spots all over the
rather dull buffy rump. However, other specimens--presumably good
BTCU--show various degrees of brown on the tail and rump, so I guess this
bird is probably just a very worn summer adult Bristle-thighed. It's in the
University of Michigan Museum of Zoology and came from Meade River, Alaska,
on the north slope, so it's an unusual distribution record.

I think that's all I have to say. If anyone has any further questions,
please e-mail me personally.

Dennis

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