Black-fronted titi monkey

The black-fronted titi is endemic to the Atlantic forest region of Brazil[7][8][4] and has a home range averaging 20 hectares.[8] The black-fronted titi is arboreal and prefers the middle to upper canopy of the forest.[5] However, it will move to the forest floor at times to forage, travel, and play.[9] Play behavior on the forest floor has been documented between black-fronted titis and marmosets in Brazil.[10]

Black-fronted titi pair

The black-fronted titi is socially monogamous[13][5][4] and is typically found in a group of two to six individuals, which includes the adult pair and their offspring.[9][4] Females give birth to one offspring per year, usually in July or August.[14] Parental care and social activities with the offspring are carried out by the male of this species, while the female only provides milk.[14] Both males and females disperse from their natal group at three years of age.[9]

The black-fronted titi is territorial and will defend territories, food resources, and mates with loud calls individually or in duets or choruses.[8][9] Loud calls are used for within and between group communication and have a high amplitude and a low frequency which allows them to be heard over long distances.[15] Loud calls are broadcast at dawn and when titis see or hear another group.[8] When confronted by a predator, duets and choruses can last up to two hours, with group members alternating between soft and loud calls.[16] There are no sex differences in calling behavior during predator interactions, both males and females will call.[5] The black-fronted titi can produce calls which encode the predator type (aerial or terrestrial) and predator location to nearby conspecifics.[17]

Characteristic of the Callicebinae subfamily, black-fronted titis can be observed with interwoven tails, a behavior thought to reinforce pair bonds and strengthen social relationships.[18][19][20]

The black-fronted titi is classified as near threatened by the IUCN due to extensive habitat loss, forest fragmentation, and an estimated population decline of more than 20% in the past 24 years.[9] Small, isolated populations are common due to fragmentation and in some areas this has led to the species going locally extinct.[4] Noise pollution can also negatively impact this species. One study found that noise from mining operations restricted the black-fronted titis long-distance communication due to the overlap in frequency between mining noise and loud calls, this is significant for a species that relies heavily on vocal communication in social interactions.[8]