Their genus name, Ateles, actually means imperfect . When spider monkeys display aggressively, they can erect the hair on their neck, shoulders, and tail base. Spider monkeys live in loosely organized groups of up to 20 individuals, usually dominated by an elder female. In the evenings the group disperses into smaller groups of 2 to 8 individuals that sleep together at a favorite perch. At sunrise the group re-forms for the next day.
Single baby is born.
Infants are not entirely independent until 36 months old. Diet Fruit and leaves. Though spider monkeys have few predators, they have been shot for food in large portions of their former range. Their numbers have also been reduced by their dependence on mature rain forest. Their habitat is being cut down for farms and wood pulp at the rate of 35,000 acres a day.