Owl-faced monkeys have unique hands and feet in that they posses elongated phalanges. These grow well during the long wet seasons. Reproduction The birth season for C. hamlyni is from May to October. The gestation period is around five to six months. These monkeys have one offspring at a time.
Twin births occur on rare occasions.
There is generally a two year interval between births. Behavior These monkeys live in groups of under ten individuals. Within these small groups, there is one dominant male. Because they live in small social groups in dense cover, their home range can be relatively small. This is possible due to the abundance of food present in this densely forested region.