High in the canopy of the rain forests in Colombia and Panama, the Colombian black spider monkey (Ateles fusciceps rufiventris) performs an important ecological service. As it climbs and swings through the tree branches, it distributes undigested seeds in its dung. The dung falls to the ground and some of the seeds eventually sprout, replenishing plant life throughout the rain forest.

The seeds come from fruit, the black spider monkey’s main source of nutrition. To a lesser degree, the monkey also eats leaves, nuts, bark, flowers, and insects.

The black spider monkey got its name because, of its black color and because as it moves through the rainforest, it uses its four long limbs, thumbless hands, and prehensile tail to climb and swing. Sometimes from a distance, it resembles a spider.

These agile primates move through the canopy using their limbs in a hand-over-hand motion, called brachiation. An arboreal species, they rarely come down from the rainforest canopy and can be seen leaping or dropping from one tree to another.

Their prehensile tail has a hairless patch at the tip that helps with grip as it wraps around branches. Markings on the patch are thought to be unique to each monkey, much like a human fingerprint.

One of the largest of the New World monkeys, the Colombian black spider monkey is classified as critically endangered by the International Union for Conservation of Nature (IUCN). Its forest habitat is disappearing as people cut down trees for fuel and timber or to make way for farmland. The local population also hunts the black spider monkey for its meat.

  1. Why does a prehensile tail matter for this species?

    • Answer

      The Colombian black spider monkey can use its prehensile tail like an additional limb, as it swings and grasps branches while climbing through the trees of the rain forest.

  2. Who are the closest relatives of the Colombian black spider monkey?

    • Answer

      There are seven species of spider monkeys included in the genus Ateles, all living in tropical rain forests of Central and South America. These “New World” spider monkeys are all of the genus Ateles, which begins their scientific names: Ateles fusciceps rufiventris for the Colombian black spider monkey, Ateles geoffroyi ornatus is the ornate spider monkey, and so on for the five other species of Ateles.

  3. How do New World monkeys differ from Old World monkeys?

    • Answer

      “Old World” monkeys live in Africa and Asia, while the New World monkeys live in Central and South America. Although related through common ancestry in Africa, Old World and New World monkeys’ facial features differ in flatness and placement of the nostrils.


having to do with trees.


form of motion in which a creature swings from one place to another using its arms.


manure, or the excrement of animals.

ecological service

benefits ecosystems provide people, such as pollination of crops and water purification.

New World

the Western Hemisphere, made up of the Americas and their islands.


appendage adapted for seizing by grasping.


type of mammal, including humans, apes, and monkeys.