Black Spider Monkey

The black spider monkey, also called the Peruvian or black-faced spider monkey, is a large, all-black monkey with a black face, very long thin limbs and a long, strong prehensile tail used like a fifth hand. Like other spider monkeys it has only a tiny vestigial thumb, so its hands work as hooks for swinging under branches (brachiation). It moves through the canopy with an agility often compared to the gibbons of Asia (Wikipedia, general species account).

Groups of up to about 55 animals split into small, shifting subgroups that feed and travel separately, and these split up or come together depending on how much fruit is available. Males stay in the group they were born in and defend its range with loud calls and barking, while females move to other groups. At Lago Caimán in Noel Kempff Mercado National Park, fruit made up about 86% of the diet, taken from 78 plant species, and in the La Chonta forest reserve about 82%. This makes the species an important seed disperser of Amazonian trees (Handbook of the Mammals of the World; Wikipedia, general species account).

In Bolivia the black spider monkey ranges through the north and centre of the country, south to about 17°S, and northeast through Noel Kempff Mercado National Park, where it is seen most often in tall forest. At the Beni Biological Station it is restricted to high forest (Handbook of the Mammals of the World). Being large and slow to breed, spider monkeys are among the first primates lost where hunting is heavy (Wikipedia, general species account). On this guide it is a target species of Madidi National Park.