File:Mandrillus leucophaeus (Drill).jpg

English: CLASSIFICATION: Mammal, Cercopithecida

HABITAT: Primary and secondary rainforest up to 2,800 m high. THREATS: Habitat destruction, hunting, bushmeat trade. DIET: Fruits (>58%), Leaves (>15%), insects (>25%), seeds, mushrooms, flowers, vertebrates (reptiles, mammals). ECOLOGY: Multimale-multi female, 1male-multi female , solitary. Fission-fusion. Group size: 3 - 63 ind. Drills are diurnal, arboreal and terrestrial animals. They live in groups of several males and several females but can also live in harems of one, dominant male and several females. Usually they form stable aggregations of several groups called hordes, of up to 65 individuals. Historically, Drills were seen in groups of up to 400 individuals. Hierarchy of females is matrilineal with ascendance rank acauisition and is maintained by aggressive behaviours, displacement and affiliative bonds. Hierarchy of males is more based on coalitions. Females can support a dominant male or challengers during male-male competitions. Adult male Drills rub their chest against tree trunks, leaving a damp patch with a musky odour.

The sexual maturity is around 3 yrs for males and 4 yrs for females. The age at first birth is around 4.5 yrs and with a birth interval of 1.5yrs.