Wednesday, May 23, 2012

Is it Winter? A Leucistic Goldfinch

For the past month, every time I look out the window and see a goldfinch I think to myself: "Wow! He's super yellow. Wonder why..."  Duh. It's summer.

My slowness on the change of seasonal molt is due to the fact that one of our most active goldfinches is a very pale male. He still looks like he's in his winter colors, which has lead my slow mind to be surprised whenever I see our normal, brightly-colored finches. We noticed him for the first time in late February, when the other male finches were starting to get their yellow patches.

The finch is leucistic meaning that its regular pigmentation is washed out. Sometimes this happens in splotches, sometimes it's an overall wash. In this bird's case it's an overall wash of his yellow feathers (with some whiter areas) - the black feathers are normally pigmented.

The funny thing is, the nape of its neck is dark. You would expect it to be the same washed-out yellow:

Even though goldfinches have two molts a year, his feathers will not improve with a molt as leucism is a genetic mutation.

Add'l Reading: Cornell's Lab of Ornithology has a great article explaining the differences between albinism and leucism. 

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