Birds in the southern part of the range are now split out as a separate species, as the chestnut-capped warbler (Basileuterus delattrii).

The bill is rather stout for a warbler, the wings are round and stubby, and the tail is long, often raised at a high angle and flicked.

While rufous-capped warblers are generally birds of tropical shrubby highlands, North American sightings tend to be in oak woodland canyon bottoms, near running water, while the birds stay low in dense vegetation.

The courtship song of the rufous-capped warbler is a rapid, accelerating series of chipping notes (chit-chit-chit-chitchitchit), somewhat reminiscent of the rufous-crowned sparrow, while the call note is a hard chik or tsik, often repeated.

[2] Rufous-capped warblers primarily feed on insects and spiders, foraging through dense brush and scanning close to the ground for movement.