The Inambari gnatcatcher (Polioptila attenboroughi ) is a species of bird in the family Polioptilidae. It is endemic to Brazil.
The holotype Inambari gnatcatcher, an adult male, weighed 6 g (0.21 oz). Its head, nape, and neck are a uniform plumbeous gray. The throat, breast, upper belly, and flanks are also plumbeous gray, palest near the bill. The lower belly is white. It has a broken white eye ring. The innermost feathers of its tail are black and the outermost approximately 80% white, with those between intergrading.
The Inambari gnatcatcher's full range is not known. All of the few records are from the Brazilian central Amazon Basin south of the Rio Solimões (the Upper Amazon) and west of the Rio Madeira. The region is called the Inambari area of endemism. "So far as is known, Inambari Gnatcatcher inhabits the canopy of tall, humid, upland sandy-soil forest" at less than 500 m (1,600 ft) of elevation.
The details of the Inambari gnatcatcher's diet is unknown but it is probably small invertebrates like that of other Polioptila gnatcatchers. It forages alone or in pairs and seems to always associate with mixed-species foraging flocks. It mostly gleans prey from foliage but also sallies out to catch flying insects.
"The nest, eggs, and breeding biology of Inambari Gnatcatcher are completely unknown."
The IUCN has not assessed the Inambari gnatcatcher. "The recent advancement of soybean plantations and general infrastructure along the BR-319 highway linking Manaus to Porto Velho in Brazil, which bisects the known range of Inambari Gnatcatcher, is a clear threat to this species."
