Zoos supplement the Colobus daily diet with browse. A Colobus troop is a cohesive group typically composed of a single adult male, three to four adult females, sub-adults, a juvenile, and an infant. The size of the troop ranges from 3 to 15. Multi-male troops have been observed as well as bachelor groups of males, but both of these groupings are believed to be temporary. These troops are highly social, mutual handling of infants by members other that the mother is believed to maintain the cohesiveness of the group.
Females spend a great deal of time in allo-grooming.
Long range communication is accomplished visually and vocally, primarily by the males jumping up and down in the trees which is accompanied by a contagious roaring. The IUCN Red Data Book does not consider these two species of Colobus to be endangered, however this is not true of all populations within each species. As with all wild primate populations, the major threats to their survival are habitat destruction, hunting and live capture for sale or trade. The hunting pressure on the Colobus monkey has been immense. Skins are used for trimming coats and dresses, but most are commonly made into circular rugs or wall hangings.