Black-throated Blue Warblers (Setophaga caerulescens) are rare migrants on Bodega Head. They primarily breed in the northeastern U.S. and southern Canada (and follow the Appalachians south) and winter in the Caribbean (a few are found along the Caribbean coast of the Yucatan Peninsula/Belize/Honduras). But lucky for us on the "Left Coast," a few stray west every now and then.
Here are two more pictures. The first is a view from above, highlighting the blue back and the white "handkerchief" or wing patch.
The second is a more distant view on a limb within the eucalyptus that the bird seemed to favor during foraging bouts. All of these images were taken in Owl Canyon on 15 October 2013.
I'm going to show two more pictures, but they come with a warning: They're not "pretty pictures." They're about a couple of details that I was curious about.
In the field I noticed that the bird had a white "chin"— just below the bill. I was curious about this feature, as I hadn't really noticed this on Black-throated Blue Warblers before. Here's a picture showing the white chin:
I didn't know if this could be particular to an individual bird, or if it could have something to do with the age of a bird. After reading a little more about Black-throated Blue Warblers, it sounds like younger birds might have white chin feathers. But since I'm new to interpreting this, perhaps someone out there might be able to help with evaluating the white chin on this bird?
And here's another feature I was wondering about: the leg/feet color. In good light, the legs/feet were pale orange (see below).
My reading also led me to believe that leg color may be an age indicator. That is, that younger birds have paler legs, and that legs become darker with age (e.g., they're black in adults).
So you can see I've started to wonder if this might be a subadult male Black-throated Blue Warbler. But I'll be the first to admit that I don't have much experience aging them, so I'd be very interested in what other people think!
P.S. Thanks to Mike for first spotting this bird on 11 October!