Owing to its recent discovery and rarity, almost nothing is known about the biology of the Caquetá titi monkey. However, on the few occasions that this social primate was seen in the wild, it was observed to live in small groups, averaging around four individuals, comprising a bonded adult pair and their offspring (2). Like other titi monkeys, this small family group probably defends a territory from other titis, with the male the most aggressive towards intruders, which are deterred with rapid and loud vocalisations and, on occasions, chasing (3) (4). The male also tends to lead the group while foraging, communicating to the rest of the group with a variety of vocal and visual signals (3). At night, titi monkeys sleep in carefully selected trees that offer protection from predators, often with the whole group huddled together (3). As largely arboreal primates, titi monkeys primarily feed on fruits in the tree canopy, but will also eat leaves, insects, birds’ eggs and small invertebrates, with feeding activity most intense in the early morning and late afternoon (3) (4).
Titi monkeys are monogamous and partners reinforce the pair bond by grooming and by perching side-by-side with their tails entwined. A single infant is born after a gestation period of around five to six months, and when it is not being nursed by the female, the infant is primarily cared for, played with, and carried by the adult male. Once weaned, the juvenile will stay within the family group until it reaches maturity, usually in its second year, when it leaves in search of its own mate (3) (4).