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
Coimbra Filho's titi fragment of the population, limiting reproductive options. The species' natural geographical distribution also contributes a threat to the species. Coimbra Filho's titi only naturally occurs in the Atlantic coastal forests in northeastern Brazil. This is a relatively small area in the states of Sergipe and Bahia. Due to this small range, any disturbances to these areas pose a larger than normal threat to the species' survival. More than anything else, however, human interference is the source of many problems to Coimbra Filho's titi. The areas around and inside its habitat are being developed, including paving roads and the promotion of