Muriquis are arboreal and active during the day (7). They live in multimale-multifemale groups (5) that may number between 8 and 80 individuals (2). Groups are not territorial; there is little aggression between members and related males often cooperate with each other (5). Social grooming between group members appears to be rare but embracing is thought to help maintain bonds (2) (5). Females tend to give birth to a single offspring in the dry season that runs between May and September (7). Males remain with their natal group, while female offspring disperse to join other groups once they have reached adolescence at 5 – 7 years old (7). Young leaves and fruit constitute a large component of the muriqui diet; individuals often feed by hanging from the branches of a tree with their prehensile tail (2) (5). Seeds, bark, flowers and some insects are also eaten during the more abundant rainy season (7).