Owl-faced guenon  (Cercopithecus hamlyni)

Owl-faced guenons are arboreal and thus spend nearly all their time in the trees where they run along the branches like squirrels (4). They have two peaks of daily activity; one in the early morning, and then again in the late afternoon or evening (6). Living in small groups with a single male (2), owl-faced guenons are apparently territorial, but avoid serious conflicts with neighbouring groups (6).

This omnivorous monkey feeds on fruit, insects and leaves (2). Their fairly large incisors are perfect for biting into fruit, and their flatter molars are suited to crushing and grinding hard seeds. They also possess cheek pouches, the advantages of which are twofold: in areas where competition for fruit is intense, the monkey can grab as much food as possible before being supplanted by another hungry monkey, at the same time, enzymes in the saliva help break down toxic compounds in unripe fruits and seeds stored in the pouches (7).