Ovulation is suppressed by lactation and births occur at two to four year intervals. Males are sexually mature in five years and females in four. These animals are social and tend to form groups of approximately thirty individuals. Groups of up to 100 have been reported. For the most part, these large groups split into smaller subgroups to forage and only for a few weeks out of the year is the whole group together.
Group size varies with habitat type and seems to depend largely on the productivity of the area.
These spider monkeys live mainly in the top of the tree canopy where they forage diurnally. They tend to feed heavily in the early morning and to rest for the remainder of the day. These monkeys are among the most agile of the primates and are often seen hanging by one limb or by the tail, which essentially functions as a fifth limb. They walk nimbly along the upper surfaces of branches and are able to pick things up with their tails. Apparently it is tolerant of some logging but depends upon large areas of tall forest.