Prairie Warbler (Setophaga discolor)
A tail-wagging yellow warbler with black streaks down its sides, the Prairie Warbler is found in scrubby fields and forests throughout the eastern and south-central United States, not on the prairies. ~All About Birds
Taken on South Padre Island, TX. A stop on his migration path.
It turns out there are a LOT of Parulidae photos floating around Tumblr.
Reposted from http://lies.tumblr.com/post/55686839110.