Collared titi in about 1904 from Maipures, which may have been a captive animal obtained in the village, since extensive and concerted efforts have failed to identify it for the entire area mentioned above; nor is it known by locals for this area. The nearest titi monkeys from Maipures in Colombia are found on the middle Tuparro River and south of the lower Vichada River. Outside of Colombia this species extends from the Napo River northward throughout the Ecuadorian and Peruvian Amazonia and throughout southern Venezuela to the Río Branco and the lower Río Negro in Brazil. South of the Amazon it
White-eared titi species within the genus "Plecturocebus". Although the exact position of species within the genus "Plecturocebus" in the "P. donacophilus" group with the Rio Beni titi ("P. modestus"), Rio Mayo titi ("P. oenanthe"), Ollala brothers' titi ("P. olallae"), and white-coated titi ("P. pallescens"). The white-coated titi has sometimes been considered a subspecies of the white-eared titi, but they are treated as separate species in the latest edition of Mammal Species of the World. The white-eared titi is a medium-sized primate with grey to orange pelage. The species does not exhibit sexual dimorphism; the male's head and body length averages while females