Puna Thistletail Asthenes helleri

Small brown bird with a very long, thin tail. Found in elfin forest and montane scrub around and above the treeline, where it forages singly or in pairs low in dense vegetation. Does not overlap with other thistletail species, and its distinctive tail shape distinguishes it from any other bird in range. Its song is a fast, slowly rising chatter of sharp, squeaky notes.