Drill (mammal)

Drill[1]
Drill at the Lincoln Park Zoo
Conservation status
Endangered (IUCN 3.1)[2]
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Primates
Family:	Cercopithecidae
Genus:	Mandrillus
Species:	M. leucophaeus
Binomial name
Mandrillus leucophaeus (F. Cuvier, 1807)
Subspecies
M l. leucophaeus M. l. poensis
Drill range

The Drill (Mandrillus leucophaeus) is a primate of the family Cercopithecidae (Old-world Monkeys), closely related to the Baboons and even more closely to the Mandrill.

Description

The Drill is a short-tailed monkey up to 70 cm long, similar in appearance to the mandrill, but lacks the bright blue and red on the face of that species. It has high sexual dimorphism in weight with males weighing up to 20 kg, the females up to 12.5 kg.^[3]

The body is overall a dark grey-brown. Mature males have a pink lower lip and white chin on a dark grey to black face with raised grooves on the nose. The rump is pink, mauve and blue. Female drills lack the pink chin.

Biology

A single dominant male leads a troop of around 20 females and is father to most of the young. This group of 20 may join others forming super groups of over 100 individuals. They are semi-nomadic seasonally, and will often rub their chests onto trees to mark their territory. They are semi-terrestrial, foraging mainly on the ground, but climbing trees to sleep at night. The females give birth to a single baby; female young remain in the troop, while male young move out to join other groups.^[3]

Longevity is up to 28 years.^{[citation needed]}

The diet is primarily frugivorous, taking a wide range of fruit, but they also eat herbs, roots, eggs, insects, and occasionally small mammals.^[3][4]

Distribution and status

Drills are found only in Cross River State in Nigeria, southwestern Cameroon (south to the Sanaga River), and on Bioko Island, part of Equatorial Guinea. It occurs in rainforest habitats. Their entire world range is less than 40,000 km².

Drills are among Africa’s most endangered mammals, and are listed by the IUCN as the highest conservation priority of all African primates.^[2] Drill numbers have been declining in all known habitat areas for decades as a result of illegal commercial hunting, habitat destruction, and human development; as few as 3,000 drills may remain in the wild, with the highest population estimate only 8,000. A total of 174 drills recovered from illegal capture are in semi-captivity at the Drill Rehabilitation and Breeding Centre in Nigeria, with high success rates in breeding recorded there,^[5] and about 40 in other zoos internationally.^[3]

Two subspecies of drill are accepted by some authorities,^[3] but are not considered distinct by others:^[6]

• Mainland drill, Mandrillus leucophaeus leucophaeus
• Bioko drill, Mandrillus leucophaeus poensis

Their closest relative is the mandrill (Mandrillus sphinx), found from southern Cameroon through mainland Equatorial Guinea (Rio Muni), Gabon and into Congo. The two species are allopatric across the Sanaga River.

References

1. ^ Groves, C. (2005). Wilson, D. E., & Reeder, D. M, eds. ed. Mammal Species of the World (3rd ed.). Baltimore: Johns Hopkins University Press. pp. 165. OCLC 62265494. ISBN 0-801-88221-4. http://www.bucknell.edu/msw3/browse.asp?id=12100573. 
2. ^ ^{a b} Oates, J. F. & Butynski, T. M. (2008). Mandrillus leucophaeus. In: IUCN 2008. IUCN Red List of Threatened Species. Downloaded on 4 January 2009.
3. ^ ^{a b c d e} ARKive - Drill (Mandrillus leucophaeus)
4. ^ Bioko Biodiversity Protection Program page on the drill
5. ^ the Drill Rehabilitation and Breeding Centre (Pandrillus) Buanchor
6. ^ Primate Info Net: Drill

External links

• "Mandrillus leucophaeus". Integrated Taxonomic Information System. http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=573030. Retrieved 1 February 2007. 
• Pandrillus - Drill and primate conservation group operating in Nigeria and Cameroon
• The Limbe Wildlife Centre (LWC) - A wildlife rescue and rehabilitation project situated in the South West Region of Cameroon.