Subject: Re: Female Eurasian Wigeons???
Date: Dec 19 09:07:34 1995
From: Dennis Paulson - dpaulson at ups.edu


>Tromping around Green Lake Saturday I noted only one Eurasian among the many
>American Wigeon, obviously a male. Which brought to mind a Christmas count
>ages ago with Bill Tweit trying to ID a female Eurasian from amongst a local
>flock of Americans. I checked several books last night and couldn't come up
>with a "simple" differentiation betwixt female widgeons. General and minor
>differences in color shades and head shape (I think) were noted, as was the
>color of the auxiliaries. In other words, not real helpful. Any ideas out
>there about separating female widgeons??
>------------------------------------------------
>Fred Bird

Female Eurasian Wigeon is differentiable from female American by being
entirely reddish-brown, head and body, while female Americans have a
head/neck that is grayer, less reddish, than the body. Female Eurasians
show up pretty well in this way. According to the literature, female
Eurasians are quite variable, some with a grayer head, but apparently even
these are still more reddish than American.

The best way to pick out female Eurasians should be to watch males in late
winter and spring, when they are mated. I have done this for many years
and have been amazed that I almost never see female Eurasians with the
males. In fact, a few females that I have found have been the only
Eurasian in *their* flock of Americans. I've also seen what seem to be
female Americans hanging out with male Eurasians (hybridization occurs with
some frequency). My feeling is that females are much less common than
males in this area, and this gibes with the fact that male ducks disperse
much more widely than females. I've speculated that 90% or more of the
Eurasians that wander into this area are males and that females are truly
rare. There are still no known breeding records of Eurasian from this
hemisphere, as far as I know.

Yes, the axillaries are differently colored in the two species, but, as you
say, this isn't much of a field mark! I haven't noticed any difference in
head shape that would be useful, but the whistled calls are quite different
in the two species, 3-noted in American and 2-noted in Eurasian.

Dennis Paulson, Director phone: (206) 756-3798
Slater Museum of Natural History fax: (206) 756-3352
University of Puget Sound e-mail: dpaulson at ups.edu
Tacoma, WA 98416