L’Hoest’s monkey (Cercopithecus lhoesti)

Also known as: L’Hoest’s guenon, mountain monkey
French: Cercopithèque De L'Hoest
GenusCercopithecus (1)
SizeMale head-body length: 54 – 70 cm (2)
Female head-body length: 45 – 55 cm (2)
Male weight: 6 – 10 kg (2)
Female weight: 3 – 4.5 kg (2)

Classified as Vulnerable (VU) on the IUCN Red List (1) and listed on Appendix II of CITES (3).

One of Africa’s most attractive primates, the L’Hoest’s monkey possesses a brilliant white ruff that frames its delicate black face. Its second most distinctive feature is the deep-set, orange eyes, surrounded by bare skin that is pale violet in adult males. The body and long legs are black with grizzled grey, except for a chestnut coloured ‘saddle’. The long tail is thick at the base and tapers to a black brush. Fully grown males can be twice the weight of females and have a conspicuous bright blue scrotum (2).

Occurs in the Democratic Republic of Congo, western Uganda, Rwanda and Burundi (2).

L’Hoest’s monkey inhabits forest up to altitudes of 2,500 metres (2).

L’Hoest’s monkeys live in groups consisting of a single male and 10 to 17 females and young, which form close bonds reinforced by mutual grooming. L’Hoest’s monkeys have a more terrestrial lifestyle than many other monkeys, always travelling on the ground, and, unusually for primates, running to flee from predators such as crowned hawk-eagles (2) (4), a strategy that requires great collective coordination in order to keep together as a group. To feed and to sleep, the L’Hoest’s monkeys will scale forest heights where they feed on the fruits of yellow wood, koso, parasol trees, wild custard apple, and the young leaves and shoots of various trees, shrubs and herbs. They also consume invertebrates (5), occasionally eat resins, bracken shoots, mushrooms and lichen (2), and have been seen carefully cleaning dirty dormant seeds that they have extracted from the soil (6).

When sleeping, L’Hoest’s monkeys frequent favourite tree spots, where they sleep as a group, out of reach of many predators. Newborn L’Hoest’s monkeys are brown and acquire adult colours over the first two to three months. The young are frequently observed entwining their tail with their mother’s (2).

L’Hoest’s monkey is a relatively little-known primate and so populations could be more threatened than is currently thought (6). Habitat loss, due to agriculture, mining and wood extraction (1), combined with hunting for bushmeat, is probably reducing population numbers in many areas (2). Even populations in protected areas are not safe from these threats; large-scale logging is known to have threatened this species in Kibale Forest, Uganda (2), and within Bwindi Impenetrable National Park, poaching, logging and the extraction of gold and charcoal occurs (7).

The Convention on International Trade in Endangered Species (CITES) lists L’Hoest’s monkey on Appendix II, meaning that any international trade in this species should be carefully monitored (3), but this does little to control hunting for bushmeat. While this species does occur in some protected areas, such as Bwindi Impenetrable National Park (7), these populations still face threats, as mentioned above. While its large distribution and largely inaccessible forest habitat protects the species’ short-term survival, the long-term prospects for the handsome L’Hoest’s monkey are not so secure (2).

For further information on L’Hoest’s monkey see:

Kingdon, J. (1997) The Kingdon Field Guide to African Mammals. Academic Press Ltd, London.

To find out more about the bushmeat trade, its problems and solutions, see:

Bushmeat Crisis Task Force:

Authenticated (26/03/09) by Matthew Richardson, primatologist and author.

  1. IUCN Red List (February, 2009)
  2. Kingdon, J. (1997) The Kingdon Field Guide to African Mammals. Academic Press Ltd, London.
  3. CITES (October, 2007)
  4. Mitani, J.C., Sanders, W.J., Lwanga, J.S. and Windfelder, T.L. (2001) Predatory behavior of crowned hawk-eagles (Stephanoaetus coronatus) in Kibale National Park, Uganda. Behavioural Ecology and Sociobiology, 49: 187 - 195.
  5. Tashiro, Y. (2005) Frequent insectivory by two guenons (Cercopithecus lhoesti and Cercopithecus mitis) in the Kalinzu Forest, Uganda. Primates, 47(2): 170 - 173.
  6. International Primate Protection League: The Mysterious L’Hoest’s Monkey of the Bwindi Impenetrable Forest (November, 2007)
  7. UNEP-WCMC (November, 2007)