It is the season for giving and receiving gifts, yet I was surprised to receive this armchair tick only yesterday. I photographed this bird in the Joshua Tree National Park in April. At the time it was a western form of the Nashville Warbler - a wood warblers 'species' with two highly separated (allopatric) breeding populations in eastern and western North America. Yesterday I read in this thread that despite the similarities in plumage between these western and eastern populations, the western birds are actually within the same clade as Virginia's Warbler, so it looks likely that these birds will be redesignated as a taxon at species level, and the name would likely be the Calaveras Warbler. In this shot the paler belly of the Calaveras Warbler is probably recognisable, certainly it seems more extensive than the bellies of the Nashville Warblers that I saw in the tree tops of the ramble in Central Park, New York, in 1996. Hmmm... must get back there for another look! Anyway, my thanks to those hard-working molecular biologists for the early present.
Another subspecies that has recently been resurrected to full specific level is the Audubon's Warbler. This spilt, from the eastern Myrtle Warbler, was officially accepted by many earlier in 2010 (for more details see http://www.aou.org/committees/nacc/proposals/pending.php). Here is a shot of a male Audubon's, also at Joshua Tree, cunningly showing off its extensive white undertail and yellow throat.
For the beauty and contrast of their plumage patterns, these wood warblers have to be my favourite group of birds on the planet. Many others are of this opinion, though in fairness they probably tend to live in the Americas... I have a slight disadvantage in being based this side of the Atlantic. An interesting revision of the taxonomy of the various species of wood warblers can be found here.