Wednesday, September 16, 2009

Identification by addition

You'll have to stay with me on this one. At Tiscornia this morning Tim and I saw exactly 2 species of waterfowl, Canada geese, and a duck I picked up flying south. The bird confused me, with vague white secondary patches and some white on the cheek area. The bird's sillhouette was odd as well. First I thought it might be a strange female RB merganser, but the shape was wrong. The whitish on the cheek made me think of a bufflehead but the shape was REALLY wrong for that. Eventually Tim got on the bird (already an outlier just given that I saw it first) and recognized it pretty quickly as a red-necked grebe. At about that point it was just close enough to also make out the white patches at both the leading and trailing part of the inner wing, though in the morning sun the leading edge patch wasn't very visible (at probably 400-600 yards away).

With apologies to Sibley and Peterson, from whose field guides I based these drawings, if you start with the drooped neck of a red-throated loon (the left most bird), add the pattern of a red-breasted merganser (the upper right bird), then you get a red-necked grebe (the lower bird) as they might appear distantly through the heat waves. Tim pointed out that the head and feet of the grebe are essentially on one horizontal axis while the body is on a parallel but higher axis, a silhouette that allows ID even farther out where you can't even see the white. Anyway, a learning experience and a year bird, one that I've seen about 3 times now in 4 years here.

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