Tepui Spinetail

The tepui spinetail is 14 to 15 cm (5.5 to 5.9 in) long and weighs 14 to 17 g (0.49 to 0.60 oz). The sexes have the same plumage. Adults of the nominate subspecies have a whitish supercilium on an otherwise dull brownish face with a few pale streaks. Their forehead is brown with some rufous touches, their crown reddish chestnut, and their back rich brown that becomes more rufescent by the uppertail coverts. Their wings are reddish chestnut and their flight feathers are slightly paler with dark fuscous tips. Their tail is dark reddish chestnut; it is graduated and sometimes the feathers lack barbs on the ends giving a spiny appearance. Their chin and throat are whitish and the rest of their underparts gray with slightly browner flanks. Their iris is chestnut, their maxilla dusky brown to black, their mandible pinkish horn with a dark tip, and their legs and feet olive-yellow to olive-brown. Juveniles have a brown crown and a more olivaceous back and more ochraceous underparts than adults. Subspecies C. d. cardonai has a more olivaceous supercilium and face than the nominate, and olivaceous brown rather than gray underparts.

The nominate subspecies of the tepui spinetail is found on the namesake tepuis where southeastern Venezuela, west central Guyana, and the northern Brazilian state of Roraima meet. Subspecies C. d. cardonai is found on tepuis in southern Venezuela. The species inhabits montane evergreen forest and woodlands, mostly between elevations of 1,100 and 2,450 m (3,600 and 8,000 ft). It also occurs locally in gallery forest in the Gran Sabana in the Venezuelan state of Bolívar.

The tepui spinetail feeds mostly on arthropods. It forages singly or in pairs and usually as part of a mixed-species feeding flock. It feeds from the forest's middle levels to its canopy. It acrobatically gleans prey from bark and debris while hitching along small branches.