About Basileuterus rufifrons delattrii Bonaparte, 1854
The rufous-capped warbler (Basileuterus rufifrons) is a New World warbler. Its native range extends from Mexico south to Guatemala, and it rarely occurs as far north as southeastern Arizona and south Texas. Birds that live in the southern portion of this species' original range are now recognized as a separate species, the chestnut-capped warbler (Basileuterus delattrii). Rufous-capped warblers typically grow to a length of approximately 12.7 cm (5.0 in). Their upperparts are plain-olive to olive-gray, with white underbellies and bright yellow chests and throats. They have a distinctive facial pattern that includes a rufous cap, a white eyebrow-line (also called a superciliary), a dark eye-line that fades into a rufous cheek, and a white malar marking. Compared to other warblers, their bill is quite stout, their wings are round and stubby, and their tail is long. This long tail is often held at a high angle and flicked. While rufous-capped warblers generally inhabit tropical shrubby highlands, sightings in North America are most often in oak woodland canyon bottoms near running water, where the birds stay low in dense vegetation. The courtship song of the rufous-capped warbler is a rapid, accelerating series of chipping notes written as chit-chit-chit-chitchitchit, which is somewhat similar to the song of the rufous-crowned sparrow. Its call note is a hard chik or tsik, which is often repeated. Like other New World warblers, this species does not actually produce a warbling sound. Male rufous-capped warblers have complex songs that include many syllable types, which are shared both within a single male's repertoire and between different males' repertoires. Males also show seasonal, temporal, and annual variation in how they use their songs. Rufous-capped warblers feed primarily on insects and spiders. They forage by moving through dense brush and scanning close to the ground for prey movement. They are not generally known to catch flying insects by flycatching from perches.
