Rio Mayo titi in deforestation is leading to the decrease in available living space for this titi monkey, forcing it to live in sympatry with another species of "Callicebus". Yet in some areas, such drastic deforestation has resulted in extremely high population density. The Rio Mayo titi is better adapted to moderately populated areas, thus overpopulation negatively impacts the species. The forests the Rio Mayo titi lives in are being destroyed for agricultural purposes, leaving little forest for the monkeys. They were only seen a few times and featured in museums until 2003 when more research was done on them. In order for
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