Occurs in north-east Brazil in the eastern part of the state of Maranhão, from the basin of the rios Mearim and Itapecuru, through Piaui, Ceará, into Rio Grande do Norte, Pernambuco, Paraíba and Apagoas. It ranges west of the Rio São Francisco, through the Cerrado or bush savanna, in Tocantins, Goiás, western Minas Gerais and part of western Bahia, and north-eastern Mato Grosso, being replaced by C. apella to the north in transition to the Amazon rain forest and the dry forests of Mato Grosso (Silva Jr., 2001). Silva Jr. (2001) indicates that the right (east) bank of the Rio Araguaia may be the westernmost limits to its range ion the north, with C. apella occurring west from the left bank, and further south, at the headwaters, giving way to C. cay. The southern limit is in the region of the Rio Grande in western Minas Gerais (Triângulo Mineiro). C. nigritus occurs to the south of the Rio Grande (Fragaszy et al. 2004, Rylands et al. 2005).