Geoffroy's spider monkey

Geoffroy's spider monkey (Ateles geoffroyi), also called the black-handed spider monkey or the Central American spider monkey, is a New World monkey from Central America, parts of Mexico and possibly a small part of Colombia. It is one of the largest New World monkeys, often weighing as much as 9 kilograms. Its arms are much longer than its legs, and its tail is prehensile, which means it can grip.

The tail can support the monkey's entire weight and works like an extra limb. Its hands have only a tiny thumb but long, strong, hook-like fingers, so it can move by swinging beneath branches. It lives mostly in the upper forest, and its diet is mainly ripe fruit, so it needs large stretches of forest. The IUCN lists it as endangered because of habitat loss, hunting and the pet trade.

Moving through the trees

Brachiation, swinging from the arms with help from the tail, is the most common way it moves below the branches. Less common forms include swinging while hanging by the tail and walking on four limbs under a branch. Its usual way to cross between trees is bridging, where it grabs a branch of the new tree and pulls it close to climb on.

When it has to, it leaps through the air. Resting, it may hang from a branch with the tail, sometimes by the tail alone. It comes down to the ground more often than other spider monkeys.

Groups that split and join

Geoffroy's spider monkeys live in fission-fusion societies of 20 to 42 members. By day the big group splits into subgroups of two to six, which search for food over large areas, and sometimes the subgroups stay apart even through the night. A group's home range can be more than 900 hectares, and the monkeys can travel about 2,000 metres a day.

They make barks, whinnies, squeals, squeaks and screams. Barks are usually alarm calls. Each monkey has a unique whinny, which may let others recognise it by sound alone, and whinnies can also call group members to a food source.

Names, tricks and art

The genus name Ateles means imperfect, a reference to the vestigial thumb, and geoffroyi honours the French naturalist Etienne Geoffroy Saint-Hilaire. Experts do not all agree on how many spider monkey species there are, and at least five subspecies are recognised.

Sometimes these monkeys rub a mix of saliva and ground leaves of the lime tree on their fur, which is believed to repel insects. The Mexican painter Frida Kahlo kept several as pets, and her 1938 painting Self-Portrait with Monkey shows this species.

On the globe

On the toy globe the spider monkey sits in the forests of southern Mexico and Central America. Look for the long arms and the curled tail.