Diagnoses of hybrid hummingbirds (Aves: Trochilidae) .4. Hybrid origin of Calothorax decoratus Gould

Abstract

Calothorax decoratus Gould 1860 is shown to be a hybrid between Acestrura heliodor and Acestrura mulsant. Plumage characters of the hybrid are a blended combination of those of the parental species. External measurements of the hybrid approximate the values expected from least squares regression of parental measurements. This is the first conclusively documented case of hybridization among the diminutive woodstars (Acestrura).