The Hamlyn's monkey (''Cercopithecus hamlyni''), also known as the owl-faced monkey, is a species of

Old World monkey Old World monkey is the common English name for a family of primates known taxonomically as the Cercopithecidae (). Twenty-four genera and 138 species are recognized, making it the largest primate family. Old World monkey genera include baboons ...

that inhabits the

bamboo Bamboos are a diverse group of evergreen perennial flowering plants making up the subfamily Bambusoideae of the grass family Poaceae. Giant bamboos are the largest members of the grass family. The origin of the word "bamboo" is uncertain, bu ...

and primary

rainforest Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainfores ...

s of the Congo. This species is exceedingly rare and known only from a few specimens; little is known about it. However these specimens tend to be widely dispersed throughout the eastern part of Congo, from the Epulu River to the

Lukuga River The Lukuga River is a tributary of the Lualaba River in the Democratic Republic of the Congo (DRC) that drains Lake Tanganyika. It is unusual in that its flow varies not just seasonally but also due to longer term climate fluctuations. Location ...

and from the

Congo River The Congo River ( kg, Nzâdi Kôngo, french: Fleuve Congo, pt, Rio Congo), formerly also known as the Zaire River, is the second longest river in Africa, shorter only than the Nile, as well as the second largest river in the world by discharge ...

to the Kabale Forest, with one example in northwestern

Rwanda Rwanda (; rw, u Rwanda ), officially the Republic of Rwanda, is a landlocked country in the Great Rift Valley of Central Africa, where the African Great Lakes region and Southeast Africa converge. Located a few degrees south of the Equator ...

. Geographically it corresponds quite closely to another species of monkey,

L'Hoest's monkey L'Hoest's monkey (''Allochrocebus lhoesti'') or mountain monkey, is a guenon found in the upper eastern Congo basin. They mostly live in mountainous forest areas in small, female-dominated groups. They have a dark coat and can be distinguish ...

''C. lhoesti''. It travels on the ground, and researchers think that it may be awake primarily by night. Schwarz (1928) grouped this species with ''C. l'hoesti'', while Elliot (1913) noted its distinctive cusp pattern on the third molar, and reassigned it to a separate genus, ''Rhinostigma''. This he believed to be an intermediate between ''

Cercopithecus The guenons (, ) are Old World monkeys of the genus ''Cercopithecus'' (). Not all members of this genus have the word "guenon" in their common names; also, because of changes in scientific classification, some monkeys in other genera may have co ...

'' and ''

Cercocebus The white-eyelid mangabeys are African Old World monkeys belonging to the genus ''Cercocebus''. They are characterized by their bare upper eyelids, which are lighter than their facial skin colouring, and the uniformly coloured hairs of the fur. T ...

''. Hamlyn's monkey has one subspecies other than the nominate. In weight, the male is much larger than the female, with the average adult weighing 7 to 10 kg, while females weigh on average 4.5 to 6 kg.Singapore Zoological Gardens Docents (1999).
Cercopithecids (Cercopithecidae)
''. Retrieved on 10 July 2006. It is thought to be a

frugivore A frugivore is an animal that thrives mostly on raw fruits or succulent fruit-like produce of plants such as roots, shoots, nuts and seeds. Approximately 20% of mammalian herbivores eat fruit. Frugivores are highly dependent on the abundance an ...

folivore In zoology, a folivore is a herbivore that specializes in eating leaves. Mature leaves contain a high proportion of hard-to-digest cellulose, less energy than other types of foods, and often toxic compounds.Jones, S., Martin, R., & Pilbeam, D. (1 ...

in diet. Some published reports indicated that Hamlyn's Monkey lives in small groups, of ten members or less, with one male and multiple females, with no data to show them occurring in monogamous groups. The species has been found only in higher elevations, above 900m and up to 4600m. In color it is generally dark gray, with a characteristic white stripe which extends from the root of the nose to the upper lip, giving it an owl-like appearance, hence the name "owl-faced monkey". The name "Hamlyn's monkey" and the scientific epithet "''hamlyni''" come from the animal dealer who first brought this species to the

London Zoo London Zoo, also known as ZSL London Zoo or London Zoological Gardens is the world's oldest scientific zoo. It was opened in London on 27 April 1828, and was originally intended to be used as a collection for science, scientific study. In 1831 o ...

. It has scent glands on its chest with which it marks its territory. Both sexes have bare, blue buttocks, and the mature male has bright red and blue genitals. The juvenile coloration is a yellow-brown coat and a pink face. In captivity it has been known to live for about 33 years. Like others of this genus, it covers a wide area in its daily travels, mostly in a search for food.

Subspecies

* ''Cercopithecus hamlyni hamlyni'' * ''Cercopithecus hamlyni kahuziensis''

Notes

External links

* ARKive
Images of the owl-faced guenon ''(Cercopithecus hamlyni)''

Hamlyn's monkey The Hamlyn's monkey (''Cercopithecus hamlyni''), also known as the owl-faced monkey, is a species of Old World monkey that inhabits the bamboo and primary rainforests of the Congo. This species is exceedingly rare and known only from a few spec ...

Mammals of the Democratic Republic of the Congo Mammals of Rwanda Fauna of Central Africa

Taxa named by R. I. Pocock {{Primate-stub