American Goldfinch with leucistic patch on head

This American Goldfinch has been coming to the feeders since before Christmas. It's identifiable by the white patch on the head. 5 February 2016.

Here it is with normal American Goldfinch, which is starting to molt into breeding plumage. 5 February 2016

We've had about 100 American Goldfinches coming to the feeders daily since December. 5 February 2016.