Just came across this photo again. This bird is actually an Audubon's Warbler, which can be distinguished from Yellow-Rumped by the yellow (as opposed to white) throat.
@ThylacineAlive Audubon's Warbler is a subspecies of Yellow-rumped rather than a different species. The Yellow-rumped Warbler has four distinct subspecies (Myrtle, Audubon's, Goldman's and West Mexico Warblers), and there has been talk of splitting them for some time (although I don't think any taxonomies do that currently).
@ThylacineAlive Audubon's and Myrtle Warblers are still retained as one species by several taxonomy groups. Proposals have come before the AOU to split them, but so far it is still declined. The basis being there is extensive (even common) hybridization between the two over a wide section of range, and there is no difference in song. However, it is agreed Setophaga coronata represents a difficult split situation, and one which warrants farther investigation. Many feel the two could be split, but also feel concrete evidence warranting the split is yet lacking.