A mandrill's face looks like a fireworks display. The ridges along the sides of the nose are vivid blue, the nose itself is bright red and the chin has a yellow beard. The colours are not paint – they come from special cells in the skin. The brighter a male's colours, the more attractive he is to females. It is nature's way of showing off.
Mandrills move through the forest in groups called hordes. Some hordes in Lopé National Park number over 600 animals – making them the largest gatherings of any non-human primate on Earth. Travelling together keeps them safe, since many eyes and ears notice predators more quickly than one.
Mandrills eat fruit, seeds, insects, mushrooms and small animals. They have large cheek pouches – like built-in lunch bags – that they stuff with food while foraging, then find a safe spot to chew in peace. Their powerful arms help them pull apart tough fruit rinds.
Male mandrills are much larger and more colourful than females. Young males start out with dull colours and gradually become more vivid as they grow. Females and youngsters are olive-green with white bellies and have red-tipped noses but without the full blue-and-red display of the adult males.