The beast seems to have yellow under-tail coverts, but nothing else about the bird seems to suggest a species with yellow under-tail coverts. Thus, I think that the bird's coloration is off in these pix. The legs look dark (perhaps with pale toes), so, if correct, most of the warbler species with entirely yellow underparts are ruled out on leg color. The yellow throat contrasting fairly strongly with the olive face suggests Pine Warbler, but the wing bars look too weak for that species, more like those of Palm. Are the tertial fringes too strong for Pine? If so, they're certainly too strong for Palm. All in all, I'm not sure of the ID of this bird. I lean toward Pine, but I think that "warbler sp." is a fine entry.