Spix's Spinetail

Spix's spinetail is 16 to 17 cm (6.3 to 6.7 in) long and weighs about 12 to 15 g (0.42 to 0.53 oz). The sexes have the same plumage. Adults have a pale gray supercilium on an otherwise grayish brown face. Their crown is rufous and their back, rump and uppertail coverts dark brown. Their lesser wing coverts are rufous, their median and greater wing coverts dark brown with wide rufous edges, and their flight feathers dark brown. Their tail is dark brown; it is graduated and the central feathers have pointed tips. Voice: The song of Spix's spinetail has been described as "a five syllable phrase, last four notes with bubbling quality: sweet! bee bee bee bee . . . . . .sweet! bee bee bee bee . . . ." and a repeated "wee'tiddledidee....wee'tiddledidee". Another vocalization is a "4- or 5-noted 'wuh-wididit' ".