ML643795825

Observation details

One can rarely know for sure with these birds, but one individual appeared to my eyes to be best classified as a hybrid. It was distinctively different from the surrounding Westerns, yet didn't immediately jump out. I felt it seemed intermediate in its field marks between the two species, and not quite far enough over on the Clark's side of the spectrum to be a pure Clark's. The (poor, because of distance) photos show things as best as I can. The bill was yellower than the Westerns, approaching a nice school-bus yellow, but had a dark upper ridge and seemed not quite as strikingly yellow as I'd expect on a Clark's. Likewise the flanks were a paler shade of gray than the Westerns, but not really all that pale. And the eye was surrounded by dark feathering with a small dusky patch of white at the lore, seemingly just slightly more conspicuous on one side than on the other. As Clark's molt into basic plumage, this facial appearance could be consistent with a non-breeding Clark's, but still seemed not as white as they usually are at this time of year. So I think it's best to call it a hybrid. I could be wrong, though!

Additional species

• Western Grebe Aechmophorus occidentalis