About Alectrurus tricolor (Vieillot, 1816)
The cock-tailed tyrant (Alectrurus tricolor) measures about 12 cm (4.7 in) in length, not counting the 7 cm (2.8 in) tail streamers that are present only on males. Adult males have a black crown and nape, with a white or whitish face. Their back is mostly black, with white scapulars and a gray rump. Their wings are black, with a white patch on the secondaries. Their tail is black, very wide, with long stiff central feathers that are twisted to sit vertically; the other tail feathers are compressed against these central feathers. Their underparts are mostly white, with a black patch on each side of the chest that connects to the nape.
In areas where adult males are black, adult females have mottled brown body coloration. Their wings are darker brown than those of males. Their tail is dark brown, short, and conventionally shaped. Their throat is white, and their underparts are whitish with brown marking on the sides of the chest. Both sexes have a dark brown iris, a yellowish bill with a lighter mandible than maxilla, and gray legs and feet. Juveniles of both sexes have similar appearance to adult females.
The cock-tailed tyrant has a disjunct distribution, with two separate populations. One population is located in north-central Bolivia. The other occurs from eastern Paraguay into Brazil, ranging from southern Mato Grosso east to Minas Gerais and south to Paraná; this range historically extended into northeastern Argentina. The species lives in multiple types of open grassland, including campos rupestres, cerrado, and humid savanna. It strongly prefers areas with tall grass over recently burned or heavily grazed areas. It is occasionally found in shrubby areas near water or shrubby grasslands. It occurs at elevations ranging from near sea level up to 1,100 m (3,600 ft).
