Which primate has the longest arms relative to its body size?

Gibbons are apes. The gibbons (family 'Hylobatidae') - together with the great apes (family 'Hominidae') - make up the superfamily of the apes ('Hominoidea'). The gibbons are also known as the small apes. With 19 species, the gibbons comprise the largest group of the apes.

The gibbons live in the evergreen tropical rainforests of Southeast Asia. They are adapted to life in the treetops. Gibbons eat mainly fruit - in addition, they eat leaves, flowers and small animals.

Gibbons exhibit numerous anatomical specialisations which are linked to their unusual locomotion. For instance, their arms are particularly elongated. Relative to body size, gibbons have the longest arms of all primates. Gibbons weigh only 5-12 kg (there is variation between the species) and are therefore the smallest of the apes. Their light build makes enables them to collect fruit from thin branches. Like the other apes, gibbons do not have a tail.