Infants are large and precocial at birth. Gestation length is 133 days. Mating takes place around August and September such that infants are born in the season of high fruit production. Behavior Aotus trivirgatus live in monogamous pairs, a behavior unique to Aotus and Callicebus among the primates. There is evidence of long term pair bonding.
Males are the primary caregiver of infants.
Care includes carrying, guarding, playing with and sharing food with infants. This demands a significant amount of energy, as the males carry infants up to four months of age and often lag behind the rest of the group. Mothers nurse their young every 2 to 3 hours. Infants are large in comparison to their parents' body mass and grow quickly. Infant size and growth might explain the evolutionary adaptation of monogamy and male parental care, since infants demand more care than a single mother can provide.