Dead Bird Quiz answers

9 02 2012

Common Merganser from above: compare the lower back/rump coloration with our Bird A.

Only one answer on the quiz this time! Wow. Was it something I said? In any case, the one response we did get, from Wouter van Gestel, brings up a good opportunity to compare black and white ducks, especially when their heads are absent. Wouter suggests that Bird A is a Common Merganser, and that species (along with Red-breasted Merganser) is right at the top of my list when confronted with a headless, reddish-footed, black and white duck body. With our Bird A, we have the luxury of a wing chord measurement, which is a diminutive 17cm. Merganser wings are generally in the 21-26cm range, so this bird is considerably smaller. The other feature of note is the color pattern of the lower back and tail. Our Bird A has a black back that ends in a wedge and contrasts sharply with a pale gray rump. Mergansers (both species) have more of a gray or speckled lower back and little contrast between it and the rump. So, what do I think this bird is? I think it’s a male Bufflehead. Though as always, I invite argument.

Compare with this male Bufflehead in flight: somewhat visible are the black back contrasting sharply with gray on the rump.

Bird B is a scaup, which is not a species we get a lot on SEANET beaches. It can be a challenge to differentiate between Lesser and Greater Scaup, but with a good spreadwing photo, it becomes substantially easier. Both species have approximately the same amount of white on the secondary feathers, but in the Lesser Scaup, that white fades quickly to a brownish gray in the primary feathers. So, our Bird B looks like a Lesser to me. (And to Wouter, I’ll point out) In the Greater Scaup, the white persists much farther into the primaries. All the more argument for spreading out the wings in your specimens before taking photos!

Greater Scaup wing: white extends well into the primary feathers.

Lesser Scaup wing: white is mainly limited to secondaries and fades to grayish brown in the first primaries.



One response

27 02 2012
Wouter van Gestel

You’re absolutely right, bird one is a bufflehead. I misjudged the ruler and I overlooked the shoe at the edge of the picture, so I overestimated the size. A common merganser is about three times the size of a bufflehead, silly me 😉

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