Living high in the forest canopy (8), the crowned guenon is an agile species, capable of leaping across large distances between trees (7). This species is generally found in groups of between 8 and 20 individuals (1), usually comprising a single male, several females and dependent offspring (9). Groups are highly vocal, with the males producing loud, booming calls to announce presence and status, as well as a series of “hacks” to indicate alarm (5). Generally only the dominant males are able to establish groups, and therefore most males lead solitary lives with limited social contact. Amazingly, this appears to drive some males to join groups of other related species such as the black colobus (Colobus satanas), where they form strong group associations, possibly at the expense of ever getting the chance to breed with their own species (9). Associations with other monkey species also frequently occur in crowned guenon groups, usually with moustached and greater spot-nosed guenons (10). The large mixed-species groups help to increase the monkeys' protection from predation, as it increases the likelihood of spotting predators such as birds of prey, and also allows sharing of information about the best foraging sites (11). The majority of the crowned guenon's diet consists of fruit, but insects are also frequently taken, along with small quantities of leaves. Unlike most guenons, populations of crowned guenon in the northern parts of its range make long distance migrations to locate seasonally abundant food supplies (2). Crowned guenon mating systems are usually polygynous, with the lone male in each group having exclusive breeding access to all the females (9). Breeding is likely to occur throughout the year, with the females giving birth to a single young after a gestation period of about five months (2).