Audubon's Warbler

Well ok, "Yellow-rumped Warbler".

 

Audubon's Warblers and Myrtle Warblers, once separate species, are now considered subspecies of Yellow-rumped Warblers. Although its throat can be whitish like the Myrtle's, summer Audubon's throats are often yellowish, as in this outstanding example.

 

Seen at Sprague Lake, Rocky Mountain National Park, Colorado.

Done