Collared titi
The collared titi (Cheracebus torquatus ) is a species of titi, a type of New World monkey. It is endemic to northern Brazil.
Five adults weighed an average of 1462 g (range 1410–1722 g) with a head-body length of around 290–390 mm and a tail length of about 350–400 mm. The face has very little hair, being limited to sparse short white hairs over a black skin. There is no sexual dimorphism, although the male has canines a bit longer than the female. The species has the smallest karyotype known for primates, 2n=16 recently described by Bonvicino et al.
The pelage is typically uniformly reddish brown or blackish brown. The tail is blackish mixed with some reddish hairs with hands and feet whitish or dark brown. This pelage contrasts in all of the subspecies with a band of white hair which extends upward from the chest and follows the neck, prolonging itself to the ears. This extension to the ears is weak, different from the other Cheracebus species which have white extending to the base of the ears.
This species is thought to be restricted to Brazil, although it may range into adjacent Colombia. It is found south to the Tapauá River or potentially the Pauiní River, west to the Apaporis and Vaupés rivers, north to the Uaupés River and Rio Negro, and as far east as the town of Manacapurú. If it ranges into Colombia, it may potentially hybridize with the black titi (C. lugens ) where their ranges overlap.
The collared titi is seen most frequently in well-developed, tall forest with a closed canopy, usually over terra firme, but not exclusively so. The species also enters extensive várzea forest, especially if the forest is tall and well-developed. Such várzea forest contrasts with the habitat needs of the coppery titi, which also uses várzea forest and more commonly so. But the coppery titi survives in low, vine-covered, "poor" forest where the collared titi is rarely found.
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 meat the species is found commonly close to indigenous settlements. The species is classified Least Concern (formerly LR) in the IUCN Red List.