MorphologyRead full entry
Volatinia jacarina are on average 10 cm in length (wing = 53 mm, tail = 44 mm, and bill = 10 mm). The male are distinguished from the brownish females and juveniles by their glossy black plumage and white underwings. The male has a concealed white spot at the juncture of the wing and body that can be seen in display flights. Females have greyish brown upperparts and pale beige below. Their throat and breast are steaked greyish brown. The iris is dark brown. The upper mandible is black, while the lower mandible is bluish grey. Feet are grey (Davis 1972; Dubs 1999).
A juvenile male has a complete postjuvenal molt in the very late fall or early winter which results in a plumage very similar to the adult female, except that the wings and tail are dull black with olive or brownish edgings. In the following early summer, there is a prenuptial body molt which produces a glossy, blue-black plumage like the adult summer male. The body molt occurs during May and June. The female also have two body molts a year, molting in the early summer to a plumage decidedly less brownish than the winter dress. As in the male, the complete molt starts as early as the last week in April (Davis 1972).
Average length: 10 cm.
Sexual Dimorphism: male more colorful
Other Physical Features: endothermic ; bilateral symmetry