The Palm Warbler occurs mostly east of the Rocky Mountains and breeds almost exclusively in Northern Canada. Some members of this species will spend winters along the west coast of the United States, however, most overwinter in the Southeastern United States and down into the Caribbean and Yucatan. The winter Palm Warbler, like most other warblers is drab brown, but the yellow under-tail area gives them away along with their habit of wagging their tail up and down as they forage on the ground. They are brave for warblers. In Florida a winter bird came up and pecked on my shoe.
The photo shows an adult heading for the breeding grounds. Photo taken in May 2018 at Magee Marsh, Ohio.