Tweeters:

This is the second consecutive winter I've seen Eurasian race Green-winged
Teals at the Black River Slough, among maybe 50 Green-wings. This supports
Michael's comments, although I don't know whether 50 birds constitute a large
teal flock. By the way, I realized that my post was ambiguous, although
Michael took it the way I meant, that is, I presume the female was a Eurasian
race, but didn't know (and haven't had time to check what the differences
are). The unidentified teal certainly was a female, not a male!

Eric Stahlfeld

I first wrote:

>This afternoon there were two male Eurasian Race Green-winged Teals and one
>(presumably) female in the Black River Slough
(snip)

Michael Price then responded:

>that 'crecca'-type male teals mess around with 'carolinensis' females is
proved by intergrades showing up in winter with intermediate features.
Interestingly, all the 'grades I've seen have been in teal flocks containing
at least one classic 'crecca'-type male, sometimes more. This is no
coincidence, I'm sure, but I can't figure out why this should be, other than
maybe, just a guess, that birds from a distinct local population in an
Alaskan/Siberian contact-zone will winter in the same place, and that one
large teal-flock typically wintering at a given location is actually
comprised of several of these discrete populations.