To all-

I took my brother (from back East) scenery/bird/whale-watching on Friday in
the San Juans. While at Limekiln Lighthouse, we spotted a flock of 8
birds about 50-75 meters offshore. After I glanced at them with the
binocs (10X), I quickly id'ed them as some kind of loon: the right size,
shape, position in the water, and white-speckled or checked pattern on
the back. I had just decided that I wasn't going to be able to give them
a REALLY positive id without my spotting scope to be absolutely sure,
whenI noted that the neck looked wrong: it was black from the side and
front. Then a bird turned away and I realized that the BACK of the head
and neck was white.

So we are talking about a bird that is decidely loon-like (and I've seen
many loons), but with a black (ok, VERY dark maybe) throat and sides of
neck blending to quite white on the back of the head and neck. No sharp
line between light and dark. The back was dark with typical loon
speckling or checkerboard pattern. We watched them for at least half an
hour as they slowly drifted south, diving frequently. Oddest thing I
have ever seen, I think. Any ideas? Was this a common loon in some sort
of strange molt stage: that's the best I've come up with?

Any help is appreciated; I'm from back East and not terribly familiar
with many of the Northwest waterbirds!

Cheers,
Jim
Research Assistant Professor
Psychology (Animal Behavior) / Regional Primate Center
University of Washington