Colobus are also found in dry semideciduous and riverine savannah. The Red Colobus completely lacks thumbs, not even having the nub found in the Black and White or Olive colobus. Like other colobus, they specialise in indigestible foodstuff. There is a strong hierarchy among the members and those with high rank have the best access to food and grooming. Only the dominant male mates.
All females leave their natal group to join other groups, often more than once.
Males are forcibly expelled and often have to fight to join another group, sometimes being killed in the process. Females may gang up to fight off or even kill strange males because infanticide is common. Probably for this reason, infants are not handled by other members until it about 1-3.5 months old. There is a lot of disagreement about the taxonomy of red colobus and between 5 and 14 species are identified by different experts, sometimes based on apparently minor differences. It is extremely shy, making quiet infrequent calls and seldom coming to the ground.