(Mandrillus leucophaeus)




Facts about this animal

The Drill (Mandrillus leucophaeus) as well his sole congener, the mandrill (M. sphinx) are large, colourful and highly sexually dimorphic forest-dwelling short tailed monkeys; males can grow up to twice the size of females. They live in contiguous ranges in the equatorial rain forest zone of west central Africa. The drill is one of the most endangered of all African primates.


Both sexes are olive brown, with a pale underside and the bare black face has an extended muzzle featuring prominent ridges along each side. Males have pink and lilac coloured testicles and a reddish region around the anus. So far two subspecies of drill are recognised. Both are similar in morphological appearance except for the hairs on the sides of the crown which are ringed yellow and black in the mainland drill (Mandrillus leucophaeus leucophaeus) and are brownish yellow with a black tip in the Bioko drill (M. l. poensis).


The drill is found in the mainland, subspecies from the Cross River in Nigeria to the Sanaga River in Cameroon, whilst the Bioko drill (M. l. poensis) is found on the southern part of Bioko. Drills are active during the day and occur in small troops of 15 to 25 animals, composed of a so called male/multifemale group formation. Female give birth to a single infant. Drills mainly forage on the ground or in the lower levels of the trees, and are generally fruit eaters.

Did you know?
That the drill is highly threatened and under enormous pressure from hunting as the sweet 'bushmeat' of this species is an important income for many people in the region? Troups of noisy drills make an easy target for poachers.


Suborder SIMIAE
Name (Scientific) Mandrillus leucophaeus
Name (English) Drill
Name (French) Drill
Name (German) Drill
Name (Spanish) Dril
Local names Sumbo
CITES Status Appendix I
CMS Status Not listed



Photo Copyright by
Arend de Haas- African Conservation Foundation



Range Cameroon, Equatorial Guinea, Gabon, Nigeria
Habitat Lowland rainforest
Wild population Unknown. By 2006 it was estimated that fewer than 5,000 individuals remained in Bioko and Equatorial Guinea (Red List IUCN 2011)
Zoo population 77 specimens registered by the International studbook (2004, excl. 150 specimens at Drill Rehabilitation Center, Nigeria), 272 reported to ISIS (2007)

In the Zoo



How this animal should be transported

For air transport, Container Note 33 or 34 of the IATA Live Animals Regulations should be followed.


Find this animal on ZooLex


Photo Copyright by
Arend de Haas- African Conservation Foundation

Why do zoos keep this animal

Due to poaching and habitat loss and fragmentation, by 1986 there were thought to be fewer than 10,000 Mandrillus leucophaeus surviving in the wild, and they were identified in the IUCN/SSC Action Plan for African Primate Conservation as one of six primates in the highest priority category for conservation needs. Since then the estimated number of remaining drills has decreased to fewer than 3.000 animals, whereas the zoo population has increased only slightly. With a view of building up a viable reserve population, an International Studbook had been established in 1982 under the WAZA umbrella, and coordinated conservation breeding programmes are operated at the regional level by EAZA and JAZA.The need to establish conservation initiatives to protect drills in the wild is known for more than two decades and, in the revised IUCN Action Plan for African Primate Conservation the drill is identified as the single species in greatest need of conservation action. Drills continue to be hunted and eaten as so called bush meat.