Scaup Uncertainty Yields Canvasback

I went back to Shark River Hills with two goals. The first was to try to find the wigeons again to see if I could get a picture of a female. But I was unable to find them so that goal went unfulfilled.

My second goal was to find the scaups again to see if I could cast more light on the issue of whether they were Greater or Lesser Scaups. The first two people to see my pictures on Saturday (when I mistakenly identified them as Common Goldeneyes) had declared them to be Greater Scaup. But looking at the distribution maps and considering that these birds didn't strike me as being that large had me thinking that these birds were more likely Lesser Scaup. I was happy to see that the Ruddy Ducks were still in the same place and that the scaups were still there. I started taking pictures.

The first shot shows three birds. The two on the left look very similar with the sharp line dividing the gray plumage on their backs from the white on their sides. The plumage of the bird on the right, however, graduates from the gray on its back to the white at the waterline. That bird also appears to be somewhat larger than the other two, although that could be an optical illusion caused by the angle of the bird to the camera.

Here's a closer look at that bird on the right. A problem with these close-up shots is there is no context to provide size information. For that matter, the size ranges I've seen for the two species intersects. A small Greater Scaup could be the same size as a large Lesser Scaup. Notice though that this one's head doesn't look be as purple as the others. Could be that this is an immature bird.

Here's a close-up of one of the birds where the two colors of the side plumage are sharply divided. This picture is the one where the bird looks most like the images of Greater Scaup you'll find around the web. But notice both the shape of this one's head and the lack of a greenish tint in the plumage at the back of the head in comparison to this picture on Wikipedia: http://en.wikipedia.org/wiki/File:Greater-scaup-male2.jpg

Another picture where the side plumage seems to fall between the two extremes seen above. But this picture again shows the notch at the back of the head.

At one point, I was lucky to get this following picture with five of the birds in the same shot. I think this shot proves once and for all that all the scaups I was seeing were of the same kind (although the notch at the back of the head is not visible in any of these birds).

Then I noticed that one of the birds in among the scores of Ruddy Ducks that had first attracted my attention was quite different from all the other birds. Seeing the red head, I jumped to the wrong conclusion that this must be a Redhead. Turns out it's a Canvasback.

This picture shows the relative sizes of the Canvasback and a scaup. The difference here strengthens my feeling that these scaup birds are indeed Lesser Scaup.