3.3.3.3 Alouatta ululata Elliot, 1912

Type: Adult male, skin and skull, No. 1911.10.16.10, British Museum (Natural History) (Napier 1976).

Type locality: Miritiba, northern Maranhão State, Brazil.

Common name: Maranhão red-and-black howler.

Alouatta ululata is distributed in the north-east of Brazil, in the north of the states of Maranhão, Piauí, and Ceará (Gregorin 2006) (Fig. 3.1). The typical pelage coloration pattern of this form was first described by Dollman (1910) from individuals collected in Miritiba (Maranhão), but he believed that the specimens that he was analyzing belonged to A. discolor, given that their pelage coloration pattern was similar to the description given by Spix (1823). Later, Elliot (1912) recognized the specimens as part of a distinct species, given that he considered that the type specimen and figure from Spix (1823) portrayed a young A. belzebul individual with the typical darker coloration, and did not accurately match Spix’s description of discolor. Furthermore, Elliot considered that Spix’s description could not be applied to any species of howler known at that time (Elliot 1913). However, Elliot found consistent differences between the specimens from Miritiba and the specimens from the west of Pará, which he considered to be A. belzebul (here A. discolor) and he therefore described it as a distinct species, A. ululata. Ihering (1914), in his review of the genus Alouatta, analyzed a number of specimens of howler monkeys from Brazil and Venezuela with the aim of resolving the problematic positioning of the forms discolor, ululata, and belzebul. Based on his analyses of cranial measurements and pelage coloration, he concluded that the three forms belonged to a single species, A. belzebul. Since then, most authors either considered ululata as a synonym (e.g., Lönnberg 1941; Groves 2001) or as subspecies of A. belzebul (e.g., da Cruz Lima 1945; Hill 1962). Gregorin (2006) considered that the specimens he analyzed from Ceará and Maranhão presented a conspicuous coloration (sexually dichromatic) not described for any individual of A. belzebul or A. discolor, and therefore agreed with the recognition of A. ululata as a distinct species. As mentioned earlier, there are no genetic studies that include specimens of this taxon, and therefore the question of their genetic distinctiveness from A. belzebul and A. discolor remains an open question.