Golden-crowned Warbler is one of the most widespread members of its family, at least for a nonmigratory species, with a geographic range that extends from northeastern Mexico breeding from Mexico south to northern Argentina. As would be expected for a species with such an ample distribution, the Golden-crowned Warbler shows substantial geographic variation, with no fewer than 14 currently recognized. subspecies These subspecies form four morphological groups: one from Mexico to Central America (culicivorus group); another in northern South America (cabanisi group); a third one in southeastern South America south of the Amazon Basin (auricapillus group); and one in the interior of southern Brazil (hypoleucus group). These groups differ in plumage, and perhaps as well as in song and calls, but do not align completely with groupings identified from genetic data. Golden-crowned Warbler takes its English name from the color pattern of its head, which is shared by all populations: the sides of the head are pale gray or grayish olive, with a dusky stripe through the eye, a darker streak along the sides of the crown, and a yellowish or golden streak down the center of the crown. The upperparts generally are dull olive or grayish. Throughout most of the range of the species, the underparts are dull yellow, but are white in the hypoleucus group (which formerly was recognized as a separate species, "White-bellied Warbler"). Golden-crowned Warbler is insectivorous, and forages in pairs or family groups in forest understory, frequently associating with mixed species flocks of other insectivores. The nest of Golden-crowned Warbler is a domed structure, with a side entrance, and is placed on the ground.