The Tapajós hermit (Phaethornis aethopygus ) is a species of hummingbird in the family Trochilidae. It is endemic to Brazil.
The Tapajós hermit is about 9 cm (3.5 in) long. The male has a metallic olive green crown and back with reddish edges to the feathers and a rich reddish rump. The tail is rounded; the feathers are dusky brownish with reddish shafts and all but the outermost have white at their base. The face is blackish with a pale supercilium and a reddish malar stripe. The chin is white and the throat black becoming rufous on the neck, chest, and belly. The female is similar but with a paler rump and buffy olive underparts with a reddish tinge.
The Tapajós hermit is found in Brazil between the Tapajós and Xingu Rivers, north-flowing tributaries of the Amazon River. It inhabits primary forest but also tolerates logged and burned areas. It has been observed in a heavily disturbed terra firme area.
The Tapajós hermit feeds on nectar and is assumed to also consume small insects and other invertebrates.
Male Tapajós hermits display to females at leks, but nothing else is known about the species' breeding phenology.
The IUCN has assessed the Tapajós hermit as Vulnerable. Its population size is not known but is thought to be declining due to deforestation and the paving of a major highway with accompanying development.
