This complex stomach allows them to exploit leaf diets usually unavailable to other primates, and it may also reduce the amount of water they must drink. Food Habits Diet consists largely of leaves. Red colobus prefer young leaves that are generally high in protein and highly digestible. Reproduction Gestation length is difficult to determine because copulation can occur 101 days prior to parturition or about halfway through the gestation cycle. There is generally a two-year span between births and infanticide is a common occurrence.
Breeding system is multimale.
Although all colobines are diurnal, some activity does occur at night in this species. Their pattern of vocalizations suggests that they engage in limited sexual and aggressive interactions after nightfall. Groups tend to be large, contain multiple males, and consist of more than 50 members. Near the onset of puberty, all females transfer to other groups. Most males either remain in their natal groups or disappear.