@Arizona Docent the group was originally composed of 1 male supposed to be umpossible to associate with other member of his specie and three females, not so young.
The group quickly breed and depending on arrivals and departures, the group account around 10-12 individuals.
Please note that the vegetation is not as luxuriant as it has been. Too many youngs for the size of the territory and a large group of beautiful but useless guereza are responsible for big loss of forest coverage.