Aythya duck was seen in the company of six or seven female
Lesser Scaup and one male Lesser Scaup (among many others ducks) at
Lake Ashurst, southeast of Flagstaff, Arizona. It was readily picked
out by its larger size and larger bill. I felt on the basis of body
size, bill size, and head shape over the 15 minutes we watched this
bird that it was a Greater Scaup. One of the other two observers was
skeptical, in part because he knew of no other records of Greater
Scaup in the area of this lake, despite its being birded regularly
by accomplished birders. The third observer, my wife Christine, was
not completely convinced. She noted that the bill's nail (which I
did not get a good look at) appeared broad, but to her the head shape
was not consistently convincing for Greater Scaup, though she agreed
that it stood out size-wise. The bird never spread its wings and so
the wing-stripe was not observed.
I tried to
photograph the bird, but was not successful in getting any good images,
as you can see. However, the images I did obtain do show some of the
features that I noted in the field.
The head shape
in the photo here looks flat-topped with the high point in front of
Here the bird is shown
next to a female Lesser Scaup. Note the striking size difference,
and also the difference in head shape.
The same bird now swimming
next to a Northern Pintail. The head shape again is like Greater Scaup,
and the sizeable bill is also apparent.
One photo shows the head
face-on. I'm not sure how to interpret this silhouette of the head.
The bill, though, looks broad. Unfortunately it is hard to tell if
the nail really is broad or if instead it's just that the photo is
Another photo, which might
show a wide nail. The erect posture makes it harder for me to associate
head shape with specific identity.
One more shot of the swimming
bird that evidences a Greater-like head.
My conclusion is that this
bird is indeed a Greater Scaup.
page was last updated on 1 December 2005.
Contact Geoff Williamson
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