Hi, tweets.

In response to Bill Hubick's posting about a Clark's Grebe at Ocean
Shores, "IMG_0890 also shows enough white in the wings to probably
lock in Clark's," I would like to add a cautionary note. I don't
think you can tell Western from Clark's by the extent of white in
their wings. Between the two museums I've worked at, there are a lot
of Western Grebe wing specimens and a sufficient number of Clark's
that I know there is complete overlap between them. Western varies
from very small white patches in the wings to almost the entire
flight feathers being white, and I don't know the extent of variation
in Clark's. The paintings in Sibley's guide are misleading in
implying a difference between the species. Some of the variation is
shown at http://www2.ups.edu/biology/museum/wings_Podicipedidae.html.
The Clark's Grebe wing has the maximum amount of white, but some have
less, and some Western have that much. Other grebes with white wing
patches are nowhere nearly so variable.

If anyone finds a dead Clark's Grebe on the beach, please save it and
try to get it to one of the Puget Sound museums (Burke Museum at UW
or Slater Museum at UPS), as they are rarely saved as specimens in
Washington.

Dennis Paulson
1724 NE 98 St.
Seattle, WA 98115
206-528-1382

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