Jon.Anderson on goldeneyes:
>The distinction between hens of the two species can be difficult (for me at
least.. :-) ) at much of a distance. Up close and personal though, the
head shape and shape of the bill is pretty definitive.

Researchers working with both goldeneye species in British Columbia
sometimes cannot distinguish females *in the hand*.
Also, goldeneyes hybridize regularly (my reference is 60 miles away
right now; I'll post details later, if they're requested).
I never feel bad about labeling a wintering female goldeneye simply
"goldeneye sp." when she defies my attempts to be certain.
--
Scott Richardson
NE Seattle
salix at halcyon.com