Thursday, February 5, 2015 Mystery diving duck and update

Seward, Alaska

BRRRRR! The northwest wind kicked into high gear today, a steady 19 mph with frequent gusts from 30 to 45 mph, but it seemed like the blasts were much stronger than that at times.  The bay boiled with whitecaps and anything that was not secured ended up in the mix. I’m glad I was able to get photos yesterday as it was much too windy at SMIC today.

The excitement began on Monday when Tasha spotted an odd duck swimming and diving in the melee of 1000+ gulls and kittiwakes at SMIC, feasting on the chopped up fish slurry from the seafood processor. The light was terrible and the birds were far, but she knew it was not a female SURF SCOTER, or a GREATER SCAUP, three of which had just shown up.

I was able to get photos of a hen and drake GREATER SCAUP with the mystery duck on Wednesday when they were much closer and in good light.
Tasha sent the photos around and got some very interesting opinions:

“Biologist: I would go with a female Ring-necked Duck x Scaup hybrid.  The bird seems to display some Ring-necked Duck characteristics (ring on neck and faintly on bill and a slightly trapezoidal head) and muted Scaup characteristics (smaller white patch at base of bill).  However, if it was a hybrid I would have predicted that the trailing white on the wings would have been a little more gray, like it is in Ring-necked, but this white is pretty bright in the wing stretch photo.  Anyways, a hybrid of some form would be my guess.”

“Waterfowl Breeder 1: Very strange, I have never seen a duck so asymmetrically Scaup on one side and Tufted Duck on the other. It’s not scientific but one way I tell Tufted from Scaup is that they always have an angry look to them.  Tufted hens look almost identical to pure-bred hens. Another thing to note is that hens never lose the white at the base of the bill while the males kind of outgrow it. In the photos the bill looks different on each side. Maybe, it could be a late hatch year bird since the plumage isn’t right?”

“Waterfowl Breeder 2: Overall shape and bill is very Scaup-like, though this particular bird is very young looking for this time of year.  Tufted Ducks are a lot smaller than Greater Scaup - I think of them as the Eurasian equivalent of Ring-necked Duck.”

“Aaron B: This is a pretty tough ID to pin on one thing, I agree with you!
Just looking at the photos I would think Lesser Scaup or Tufted Duck.
One general characteristic of hen Tufted Ducks as opposed to the Lesser Scaup is the more obvious contrast between a dark back (wings) and lighter side.  I think of the Tufted Duck head as having a more horizontally elongated circle and the Lesser Scaup being more vertically elongated.

Is there any sign of a tuft or rough feathers on the back of the head? This should be lower down the back of the head than the top "tuft" of a Lesser Scaup adding to the Tufted Duck's more wide instead of tall look. I suppose some birds may not show any, but this is usually behavioral. The deep brown back coloration looks good, did you notice a clear distinction in the back and side coloration? But I agree, it keeps my interest!”

Any other opinions? I'll post updates if Tasha or I get any. Thanks too to Sadie U and Robin C for their help tracking this bird.

A Tufted Duck would certainly be a first for Seward, but this little diving duck, however tantalizing, does not seem to be one. The identity remains a mystery to us humans, but we will be better prepared should a rare Tufted Duck ever appear. And why not? It could join the STELLER’S EIDER.

02-07-15 Update:
A few more opinions have ruled out Tufted Duck which has white on the secondaries all the way out to the tip of the primaries. In both TUDU and Ring-necked Ducks the bill is black-tipped as in “dipped in ink” that totally obscures the outline of the moderately sized nail. Greater Scaup have large nails.

The amount of white in the secondaries and lack in the primaries suggests a LESSER SCAUP, as does the small black nail on the bill tip. The head shape and body size are not typical for any of the four Aythya species mentioned above; possibly it is delayed in development or compromised by a heavy parasite load or something similar. It is most likely a juvenile male with the possibility that it could be a Lesser X Greater Scaup hybrid.

Happy Birding!

Carol Griswold

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