About Gubernetes yetapa (Vieillot, 1818)
This species is commonly called the streamer-tailed tyrant, with the scientific name Gubernetes yetapa (Vieillot, 1818). Its body alone measures approximately 35 cm (14 in) long; when including the tail, the total species length reaches 42 cm (17 in). The sexes have nearly identical plumage: females are smaller, slightly duller in color than males, and have shorter tails. Adult streamer-tailed tyrants have a pale gray forecrown and supercilium, a darker gray crown, and a black line running through the eye. Their upperparts are gray, with dark brown shafts running along each feather. Most of their wings are blackish, with a large cinnamon patch at the base of the primaries that is clearly visible when the bird is in flight. The tertials on their wings have light brown to sandy brown edges. Their blackish tail is long, graduated, and deeply forked. Their throat is white, with a dark chestnut collar below it that curves upward to a point behind the eye. Their breast and sides are pale gray, with faint dark shafts on the feathers, and their belly is white. Juveniles are much duller than adults, have a much shorter tail, and have brown blotches on their upperparts. Adults have a dark iris, a stout black bill, and black legs and feet. The streamer-tailed tyrant has a disjunct distribution. One population lives along the upper Beni River in northwestern Bolivia. The other, much larger range extends from eastern Bolivia east through southern Mato Grosso, northern Mato Grosso do Sul, Goiás, and Minas Gerais to far southern Bahia in Brazil. It continues south through eastern Paraguay, western Rio Grande do Sul in Brazil, and the Chaco, Corrientes, and Misiones provinces of northeastern Argentina. It has also been recorded as a vagrant in Uruguay. The streamer-tailed tyrant lives in wet grasslands and marshy areas near streams and shrubby areas, and also occupies groves of moriche palm. Overall, its elevation range reaches from sea level to 1,000 m (3,300 ft) in Brazil, and up to 1,100 m (3,600 ft) in other areas.
