Spider monkeys are the most acrobatic of the South American monkeys. They have a powerful, well-developed prehensile tail that can be used as a “hook” for hanging from branches, or as a “hand” for gathering and holding their favorite foods.

They prefer to eat fruits, along with nuts, shoots, buds, new leaves and flowers. When eating fruits, a family of spider monkeys drops many to the ground, where they are eaten by agoutis, which destroy many of the seeds. The monkeys, however, swallow the seeds along with the fruit, then carry them away and deposit them in their dung elsewhere in the forest. Thus, the monkeys are another species that aids the re-growth of the forest.

Spider monkeys spend most of their time in the forest canopy. Although they are remote from ground water supplies, they have been observed drinking from the "water cups" of tank bromeliads.  Their high habitat protects them from most forest predators. They may be eaten by cats and large snakes like boa constrictors; young monkeys are also preyed upon by Harpy eagles. The major threat to their survival is deforestation, which has led to the fragmentation and isolation of populations.