Distribution

West Amazonia. Red-billed Ground-Cuckoo occurs in the upper Amazonian lowlands of Peru in Loreto and northern Ucayali (east of the Río Napo and the Río Ucayali) and in upper Amazonian Brazil, Amazonas state east to the west bank of the Rio Negro (north of the Amazon) and of the Rio Purus (south to the Amazon) (Haffer 1977, 1997, Payne 2005).

Observations of Red-billed Ground-Cuckoos have also been made in Amazonas, Colombia (Puerto Umbría, Putumayo; Willis 1982, 1988, Cuadros 1991). There also are hypothetical records of Red-billed Ground-Cuckoo in eastern Ecuador, at Yuturi Lodge 180 km east of Coca in Orellana Province, and north of the Río Aguarico in Sucumbios Province, (López-Lanús 1999, Ridgley and Greenfield 2001), which are awaiting additional evidence (Nilsson et al. 2014).

There is also a sight record of an unidentified Neomorphus sp. in Jaú National Park, west of lower Rio Negro in Amazonas state, Brazil, which could be attributed to N. pucheranii (Borges et al. 2001).

Endemic to South America. Nonmigratory.

Red-billed Ground-Cuckoo occupies tropical moist lowland evergreen forest of upper Amazonia. Prefers lowlands, up to 700 m, and on moderately hilly and well drained soils (Parker et al. 1996, Ridgley and Greenfield 2001, Erritzöe et al. 2012). In northeastern Peru, found in forest with a canopy about 20 m high with some taller and emergent trees (25-30 m; Siegel et al. 1989).

None reported.

No fossils have been found. However, Red-billed Ground-Cuckoo is thought to have originated in the Napo area of the North Amazon during the Quaternary or late Tertiary due to a substantial sea-level rise that would have fragmented the Amazonian lowlands and favored active allopatric speciation (Nores 1999).