Yellow-rumped (Myrtle)

I've copied this from the Cornell Lab website for clarity on this sub-species of Yellow-rumped Warbler.

REGIONAL DIFFERENCES - (The Yellow-rumped Warbler has two distinct subspecies that used to be considered separate species: the "Myrtle" Warbler of the eastern U.S. and Canada's boreal forest, and "Audubon’s" Warbler of the mountainous West. The Audubon’s has a yellow throat; in the Myrtle subspecies the throat is white. Male "Audubon's" Warblers have more white in the wing than the "Myrtle" Warbler. Female Audubon's have less distinctly marked faces, lacking the dark ear patches of the "Myrtle" Warbler. Intermediate forms occur where the two subspecies' breeding ranges overlap, such as in the Canadian Rockies.)

F/8, 1/400th, ISO 640, 1D M3, 300mm f/2.8 + Kenko 2x around 8:00am