Rutter’s Red Titi Monkey, Callicebus rutteri

The Rutter’s red titi monkey was described in 1923 by Oldfield Thomas, from an animal collected at Puerto Leguia on the Rio Pachitea, Peru.
The species was described as being “reddish-brown with bright red head and limbs, and a black and grey tail. Back warm reddish brown, not as greyish as in caligatus and its allies. Head rufous, the cheeks and underside brighter and richer, a deep rich “morocco-red”; forehead with a narrow band of whitish, no so broad as in leucometopa, nor so whitish as in subrufus. Hairs on ears red. Limbs brilliant rufous distally above and wholly below, the shoulders and hips more brownish, like the back, but without the distinct greyish area found in subrufus. Hands and feet wholly rich rufous, except that there are a few whitish hairs at the tip of the toes. Throat, chest, and narrowed middle area of belly bright rufous, in continuity with the inner side of the fore-limbs. Tail greyish black proximally, the tip for about three inches above and eight inches below white or greyish white.
It differs from related speciesby its generally more rufous colour, the more rufous crown, the absence of the marked greyish areas on the shoulders and hips, and by its practically wholly rufous hands and feet.

It is generally considered as a synonym of Callicebus leucometopus.