Tyrant-flycatchers (Tyrannidae)

Northern Beardless Tyrannulet (Camptostoma imberbe) - HBW 9, p. 275

French: Tyranneau imberbe German: Nördlicher Blasskleintyrann Spanish: Mosquerito Imberbe
Other common names: Beardless Flycatcher

Taxonomy: Camptostoma imberbe P. L. Sclater, 1857, San Andrés Tuxtla, Veracruz, Mexico.
Forms a superspecies with C. obsoletum; the two overlap slightly without intergrading in WC Costa Rica. Birds from S USA (Arizona) and NW Mexico, supposedly longer-billed, more olive above and more yellow below, described as race ridgwayi; others, from Cozumel I, named as thyellophilum on basis of minute differences in mean culmen length in a small sample; both, however, considered indistinguishable from other populations. Monotypic.

Distribution: S USA (S Arizona, S Texas) and Mexico (including Yucatán Peninsula and islands of Holbox and Cozumel) S to NW Costa Rica.