Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Mammalia Primates Cercopithecidae

Scientific Name: Mandrillus leucophaeus
Species Authority: (F. Cuvier, 1807)
Infra-specific Taxa Assessed:
Common Name(s):
English Drill
Spanish Dril
Taxonomic Notes: Mandrillus was regarded as a subgenus of Papio by Dandelot (in Meester and Setzer 1977) and Wolfheim (1983), but recent molecular and chromosomal analyses suggest that Mandrillus is less closely related to Papio than is Theropithecus. This taxon is commonly subdivided into two subspecies: M. l. leucophaeus, from the mainland, and M. l. poensis from Bioko. Grubb et al. (2003) commented that on present evidence the two forms appear very similar.

Assessment Information [top]

Red List Category & Criteria: Endangered A2cd ver 3.1
Year Published: 2008
Date Assessed: 2008-06-30
Assessor(s): Oates, J.F. & Butynski, T.M.
Reviewer(s): Mittermeier, R.A. & Rylands, A.B. (Primate Red List Authority)
Listed as Endangered as the species is thought to have undergone a decline well exceeding 50% over the past 30 years, mainly as a result of heavy hunting pressure and continuing habitat loss.
Previously published Red List assessments:
2000 Endangered (EN)
1996 Endangered (EN)
1994 Endangered (E)
1990 Endangered (E)
1988 Endangered (E)
1988 Endangered (E)
1986 Endangered (E)

Geographic Range [top]

Range Description: The distribution on the Drill is uncertain, but it appears to have a very restricted distribution in western and south-western Cameroon (including Korup National Park) and south-eastern Nigeria, between the Cross River and Sanaga River. There is one record from just south of the lower Sanaga at Ongue Creek (Grubb 1973). It is also present in the south-western corner of Bioko Island.

There are two subspecies: M. l. leucophaeus occurs on the mainland, between the Cross River and Sanaga River valleys; M. l. poensis occurs only on Bioko Island.
Countries occurrence:
Cameroon; Equatorial Guinea (Bioko); Nigeria
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: They are not common in any part of their range, but they manage to persist in a number of areas where they were presumed to be extinct. On Bioko, Drills have declined by a little over 30% over the period 1986-2006; fewer than 5,000 are estimated to remain on Bioko (Hearn et al. 2006).
Current Population Trend: Unknown
Additional data:
Population severely fragmented: No

Habitat and Ecology [top]

Habitat and Ecology: Drills are a semi-terrestrial species, found in lowland, submontane rainforest up to 1,000 m. They occur in mature secondary forest, but only infrequently in young secondary forest. Drills are omnivorous and forage extensivly on the ground probably consuming a large variety of invertebrates. They have a flexible social organization, and live in harems of up to 25 individuals which periodically come together to form bands consisting of up to 200 animals.
Systems: Terrestrial

Threats [top]

Major Threat(s): This species occupies a relatively small range, and is severely threatened by habitat loss. They have been totally displaced in the heart of their range, in Cameroon between Douala and Edea, due to clear-felling for chipboard factories and settlement. Reafforestation has involved the planting of non-palatable exotic species such as Eucalyptus and Gmelina arborea. Logging roads open areas to cultivators, causing further habitat loss, and allowing increased access by hunters. They are hunted for their meat, and all members of a harem are often shot en masse. Excessive hunting has resulted in a particularly marked declines in Nigeria and on Bioko. They are also frequently killed in defence of crops such as bananas, cocoa, and manioc, and this is likely to increase as cultivation expands.

Conservation Actions [top]

Conservation Actions: Listed under Appendix I of CITES and as Class B under the African Convention. This species is found in Korup National Park (Cameroon) and the Cross River National Park (Nigeria). It is also found in the southern, nominally-protected part of Bioko. Any area containing adequate populations should be immediately protected, and all populations need to be rigorously protected against hunting - for example, the drills inhabiting the forests of the Mbe Mountains and on the Obudu Cattle Ranch, Nigeria. A number of animals are held in captivity, but all of the mainland subspecies.

Citation: Oates, J.F. & Butynski, T.M. 2008. Mandrillus leucophaeus. The IUCN Red List of Threatened Species 2008: e.T12753A3377185. . Downloaded on 13 October 2015.
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