This bird appeared briefly in mid-October at my birdbath this year (in Santa Rosa, CA). Clearly it was unusual, but nothing in the books makes any sense. We are near a heavily wooded area (but in suburbia) and seem to be on a north-south coastal migration path (more or less). It's most noticeable features are an all-yellow head, neck, breast, and back and mottled white-grey-dark grey wings. It is about the size and shape of a lesser goldfinch, but I'd say a trifle bigger and plumper. At first I thought it was a prothonotory warbler, because that was the only thing with an all-yellow head that made any sense. Today (November 8) the bird was back and at the feeder and bird bath for much of the day, along with the usual birds we see (lesser goldfinches, house finches, various sparrows, quail, titmice, chickadees, etc.). Today I got a good look at it. It definitely is not a warbler of any kind (and a prothonotory warbler here is a rarity anyway). It has a typical seed-eater bill, not a pointed, dark bill like a warbler. The bill and legs are a pale, pinkish-ivory color. The eye is dark. There is no eye ring. There is no streaking anywhere on the yellow areas. The underside tends slightly toward the olive, but the whole upper part of the bird is a clear lemon yellow--not as deep yellow as an American goldfinch. It's more like a parakeet yellow, but this bird does not have a hooked bill or a pointed tail. The tail is finch-like. It's medium-long and notched, although not deeply. From underneath, the edges and the tip of the tail are slightly darker, but not a lot. It's plain yellow underneath. There are no distinct wing bars or tail markings in flight that I could see. I'm stumped. There is no bird in the Western Birds book that has a completely yellow head that makes any sense. Note that this has the look of an adult male, not a juvenile, but I don't know that for sure. I wasn't able to take a good picture, but did get two bad ones that might help. I'm new here, If someone can tell me how to post the photos, I will.