The brown titi monkey, Callicebus brunneus
In 1842 Wagner described this new species of titi monkey, based on specimens collected by von Pelzen along the Rio Marmoré, near the Cachoeira da Bananeira, Brazil. In a later publication (1848) he described the species as “resembling C. caligata in size, stature and black band on forehead but differing by the chestnut-brown colour, the complete black hands and the dark tail. Resembles C. nigrifrons , but the C. brunnea differs by its colouration, the small size and the short pelage with slack and not bushy hairs. The dominant colour is a shiny rusty chestnut-brown with light brownish tips. This colour becomes towards the head very light yellow-brownish, while it becomes darker on the sides of the body and the limbs; the hands are completely black. The hairs are at the first half dark rusty-brown, then black with light yellow-brownish rings. On the neck and back of the head the terminal part of the hairs is uniform light brownish-yellow, showing only this colour, which is sharply demarcated from the rest of the head. The head is on the anterior half covered with shiny, coal-black hairs, which are at the back mixed with rusty-red, while the hairs here have short foxy-red tips. The dark colouration of the forehead is separated sharply from the light colouration of the back of the head over the middle of the skull. The sides of the face are also black. The ear is covered is rather long black hairs. The underside of the body is covered sparsely with black-brown, vaguely ringed hairs. The tail is uniform dark-brown, with very faded annulation, but becomes lighter on the tip”.
In literature, titi monkeys from southern Peru are often called Callicebus brunneus, but their correct identification is C. urubambensis or C. toppini.
Callicebus brunneus is restricted to Rondonia, Brazil.