The black-horned capuchin is a social monkey that lives in groups of approximately 6 to 20 individuals, which typically comprise more females than males. Hierarchies exist within both the males and females of the group, with the alpha (dominant) female being submissive to the alpha male (1).
The female gives birth to a single young at a time after a gestation period of 151 to 155 days. If the young survives, the female will give birth again two years after the young has been weaned; however, if the infant dies, the female may reproduce much sooner. Females reach sexual maturity at the age of four, while males usually become sexually mature a few years later (6).
Capuchin monkeys are the most omnivorous of the Neotropical (tropical American) primates, having an extremely varied diet consisting of fruit, other plant matter, insects, spiders and small mammals (7). There have been sightings of capuchin monkeys hunting for small rodents, although most of the meat in their diet is thought to come through the foraging of carcasses (8). The black-horned capuchin spends 70 to 90 percent of its day foraging for food (2).
Although little is known about tool-use in the wild, advanced behaviour in tool making has been documented numerous times in black-horned capuchins in captivity, such as making modified twigs to probe holes and the use of stones to crack open ice cubes to retrieve hidden food (9).
As with many primates, communication between members of a black-horned capuchin group consists of a wide range of different verbal communications, body language and facial expressions. One particular method of communication documented within this species is the ‘scream embrace mechanism’, a loud, high-pitched call followed by an embrace which tends to be used to reunite members of the group after prolonged absences. This occurs most frequently between the males of the group (10).