This large flycatcher is a resident of wet South American grasslands and is named for its long, deeply forked tail, which plays a role in courtship. A pair will perch facing each other, bobbing up and down and fanning their tails while calling continuously.
The Streamer-tailed Tyrant can be found at the Barba Azul Reserve in Bolivia, created by ABC and
Asociación Armonia in 2008 to protect unique Beni savanna habitat and the critically endangered Blue-throated Macaw. Other unique and threatened species that can be found at Barba Azul include the Cock-tailed Tyrant, Orinoco Goose, and Buff-breasted Sandpiper, which stops here during migration.
The Bolivian population of the species found in Barba Azul is isolated by over 400 miles of Beni savannas from populations in Brazil, Paraguay, and Argentina. Further study may reveal that it has evolved into a distinct species.
Bennett Hennessey of Armonía remarked: “The Streamer-tailed Tyrant has been recorded along the edge of the forest islands in Barba Azul. It comes and goes, sometimes present for several days, and then is off somewhere else in the reserve for other periods. We hope one day to be able to study the habits of this Bolivian variant in more detail.”
The Streamer-tailed Tyrant is usually found singly or in pairs. The birds perch on low trees, bushes, and telephone wires, sallying out to forage over marshy areas for insects. Its loud, repeated "wurreep" call makes it a conspicuous resident throughout its range.