Subject: [Tweeters] Wahkiakum County Aythya
Date: Sun Feb 7 15:57:20 PST 2021
From: Bill Tweit - bill.tweit at gmail.com

At least one of the diving ducks in Wahkiakum that has been called a Tufted
Duck is actually a hybrid Tufted X scaup. Greg Harrington got very good
photos of the male diving duck with a bit of a tuft that has been observed
there, and the combination of a dark gray back, that is clearly lighter in
tone than the black breast and blackish head, and the very short tuft,
indicates that it is a hybrid. This bird is clearly white-sided at this
point, His eBird checklist and good photos (
https://ebird.org/checklist/S80521019) are from Feb 6.

There is a wrinkle to this, as there are photos of Aythya with slight tufts
from the same area with brownish sides from late January. The best of
those (from Jake Bonello on Jan 28) show that the brown flanks are
actually mottled white, The simplest explanation for this is that they
are all the same bird, a young male that is rapidly transitioning from
immature to adult plumage, It is possible that two individuals are present,
so I would appreciate continuing eBird reports from the area. The
brown-flanked bird should continue to be reported as a Tufted, rather than
Aythya (sp) so I can see them in the review queue. If there aren't any
further reports of the brown-flanked bird, we may conclude that my simple
hypothesis is best supported by the evidence and request observers to
change their checklists.

All of this may have observers wondering about the Clark County bird. That
bird is pretty clearly a female, and all of her field marks including neck
thickness, bill shape as well as plumage characters fit female Tufted very
well. While it may be very difficult to detect a hybrid female, at this
point, I don't see any reason to suspect hybrid origin for this bird.
There was at least one report of a male in the same area, Will Brooks found
a hybrid male Tufted x scaup, but I don't think it was resighted. It might
be the same white-flanked individual found in Wahkiakum, but it had white
flanks when seen so isn't the brown-flanked bird photographed in Wahkiakum
in late January. I encourage observers to continue to submit photos of
all Aythya with any sign of a tuft, to help with further tracking of these
birds.

This is also a great example of the utility of eBird, as it gives all of us
a very convenient way to examine photos and written descriptions, and track
plumage changes over time.

Bill Tweit
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