DistributionRead full entry
Range DescriptionThe type locality for Alouatta discolor is given as Forte Curup (= Gurup), Par, Brazil. Gregorin (2006) explained that this was on the southern margin of the Rio Amazonas, not on the Island of Gurup (opposite), which is occupied by red howler (Fernandes 1994), presumably Alouatta macconnelli. It would seem that this would be the easternmost limit to the range of this species, whjch extends west in a narrow strip along the south bank of the Rio Amazonas and south through the interfluvium bounded by the rios Tapajs and Juruena in the west and the rios Xingu and Iriri in the east (Gregorin 2006). Alouatta discolor is the howler monkey of the Rio Curu basin.
Bonvicino et al. (1989) indicated that Alouatta discolor occurs on the Islands of Maraj and Caviana, and Mexiana, but here we follow Fernandes (1994), Ferrari and Lopes (1996), and Gregorin (2006) who agree that Alouatta belzebul is the howler occurring there.
Between the lower Xingu in the west and the Tocantins the identity of this species is in doubt (A. Rylands, pers comm.).