Thursday, July 24, 2008

Odd-ball out the window.


American Robin, taken through Venetian blinds during a social event. I take a camera to a party, and this is the only picture I come home with.

This American Robin caught my eye because of the scattering of white feathers on its head, wing, back and leg. I had previously known the patchy absence of pigmentation in birds’ feathers as leucism. I.e., this was a leucistic robin. Apparently the meaning of the term is not so clear-cut. Some authorities refer to leucism as the state when there is an overall reduction in pigmentation, particularly of melanin, in the feathers, so that the normal pattern of plumage results, but appears fainter, or “washed out.” Others have used the term to describe birds that possess melanin, but that the pigment is lacking from the feathers, resulting in an all-white bird with pigmented soft parts and dark eyes. Still others have used leucism as I had understood it, but others instead would refer to this bird as “partially leucistic.” A more thorough discussion of the various usages of leucism is given here.

If it were a chicken, it could be called “pied” (no hint of its culinary fate), but this term has no formal scientific standing. Sport? Mutant? Odd-ball?

I hope the other robins don’t give him a hard time about it.

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