Lives in groups led usually by a single dominant male. The red-tailed monkey is occasionally found together with groups of the blue monkey (Cercopithecus mitis), and even though social interaction between the two species is infrequent, crossbreeds have been found in four forests, one of which is the Kibale National Park. The hybrids are capable of reproduction and resemble blue monkeys more than red-tailed  monkeys.  Moreover, at least female crossbreeds appear to enjoy a favorable position in the social hierarchy.