Collared titi causes them to give alarm peeps, probably because they must be especially alert to predators. A margay was detected alongside a dead collared titi during recent censuses on the Purité River in Colombia, although the monkey was not freshly killed. The local group was no longer observed after this. The collared titi is not considered to be endangered, but where there are many colonists this primate tends to disappear, due to deforestation. The species is commonly hunted and eaten by indigenous peoples or used as bait for hunting larger carnivores or for fishing; however, where there is plenty of forest
Coimbra Filho's titi of Bahia and Sergipe in coastal northeastern Brazil. Coimbra Filho's titi, like most titis, is a folivore-frugivore, with a diet consisting mostly of leaves, but also including various fruits. Coimbra Filho's titi generally lives in small groups consisting of three to five members. Such a group generally contains a breeding pair and its direct offspring that have yet to reach sexual maturity. However, upon reaching sexual maturity, individuals leave their natal groups, and often immigrate to new areas. Their range size varies, with some occurrences recorded of ranges as small as , and others larger than . Coimbra Filho's titi