The yellow-rumped warbler (Setophaga coronata) is a North American bird species combining four closely related forms: the eastern myrtle warbler (ssp coronata); its western counterpart, Audubon's warbler (ssp group auduboni); the northwest Mexican black-fronted warbler (ssp nigrifrons); and the Guatemalan Goldman's warbler (ssp goldmani). It is 4.7 to 5.9 inches long and is characterized by yellow patches on the crown, flank, and rump. The Audubon's subspecies, which is the most common in the western United States, also has a yellow throat. As a species that winters in the COSA area, it can be spotted from September to May in the COSA.