Crested Mona Monkey

Living high in the forest canopy (8), the crowned guenon is an agile species, capable of leaping across large distances between trees (7). This species is generally found in groups of between 8 and 20 individuals (1), usually comprising a single male, several females and dependent offspring (9). Groups are highly vocal, with the males producing loud, booming calls to announce presence and status, as well as a series of “hacks” to indicate alarm (5). Generally only the dominant males are able to establish groups, and therefore most males lead solitary lives with limited social contact. Amazingly, this appears to drive some males to join groups of other related species such as the black colobus (Colobus satanas), where they form strong group associations, possibly at the expense of ever getting the chance to breed with their own species (9). Associations with other monkey species also frequently occur in crowned guenon groups, usually with moustached and greater spot-nosed guenons (10). The large mixed-species groups help to increase the monkeys' protection from predation, as it increases the likelihood of spotting predators such as birds of prey, and also allows sharing of information about the best foraging sites (11). The majority of the crowned guenon's diet consists of fruit, but insects are also frequently taken, along with small quantities of leaves. Unlike most guenons, populations of crowned guenon in the northern parts of its range make long distance migrations to locate seasonally abundant food supplies (2). Crowned guenon mating systems are usually polygynous, with the lone male in each group having exclusive breeding access to all the females (9). Breeding is likely to occur throughout the year, with the females giving birth to a single young after a gestation period of about five months (2).

The crowned guenon occurs in a number of protected areas throughout its range, and is therefore safeguarded, to some extent, from habitat loss (1). In order to protect this species against unsustainable levels of international trade, the crowned guenon is listed on Appendix II of the Convention on International Trade in Endangered Species (CITES) (3). In addition, this species is listed on Class B of the African Convention on the Conservation of Nature and Natural Resources, and therefore legal hunting requires authorisation (1) (12). Unfortunately, despite these controls, the bushmeat trade for the crowned guenon—along with many other species—continues to grow (13) (14). To combat this, on Bioko, the Bioko Biodiversity Protection Program is working to protect the island's threatened wildlife by patrolling protected areas to deter hunters, and by developing research and educational programs (13). At an international level, the Bushmeat Crisis Task Force, a consortium of several conservation organisations, is working with governments, organisations and the general public, in order to eliminate unsustainable and illegal bushmeat hunting practices worldwide (14).

The crowned guenon is a widespread and common African forest monkey, with distinctive facial markings and prominent tufted ears (4) (5). Currently this species encompasses seven different subspecies, which vary in location and, to a small degree, in appearance. Nevertheless, they generally possess a finely speckled brown and grey coat, becoming black on the lower limbs and on the lower part of the long tail (2) (4). In contrast, the rump, belly and the insides of the legs are golden-yellow and, in the male, the scrotum is blue (4). Certain subspecies, such as the Congo Basin Wolf's monkey, have more extensive golden colouration, extending across the entire hindquarters (6). The crowned guenon's face is mostly dark blue, except for the muzzle, which is pink. The fur surrounding the face is yellow, and characteristically marked with a wide black stripe running from the side of the eye to the ear and across the middle of the forehead where it forms a small crest (2) (4). In addition to these markings, the Congo Basin Wolf's monkey has a conspicuous white band running across the brow (7).

The crowned guenon is generally found in moist primary and secondary forest, in lowland and montane regions (1) (2).

The overall range of the crowned guenon, combining the separate distributions of the seven subspecies, extends throughout much of Central Africa, from south-east Nigeria, as far east as Uganda and Rwanda, and as far south as northern Angola. Taken individually, subspecies Cercopithecus pogonias pogonias is found on the island of Bioko and also in Nigeria and northern Cameroon. Cercopithecus pogonias nigripes is found in Equatorial Guinea, Gabon, Congo and extreme north-west Angola, around Cabinda. Cercopithecus pogonias grayi ranges from southern Cameroon, east to the Central African Republic, and south to Congo and the Democratic Republic of Congo north of the Congo River. Cercopithecus pogonias denti occurs in the eastern Democratic Republic of Congo as far east as western Rwanda and Uganda, and as far north as the Central African Republic. Both Cercopithecus pogonias wolfi and Cercopithecus pogonias elegans are only found in the Democratic Republic of Congo, with the former located in the western and central regions, between the Congo and Sankuru Rivers, and the latter in central and southern regions between the Lomami and Lualaba Rivers. Cercopithecus pogonias pyrogaster is found in south-western Democratic Republic of Congo and northern Angola, between the Rivers Kwango and Kasai-Lulua (1).

Classified as Least Concern (LC) on the IUCN Red List (1) and listed on Appendix II of CITES (3). Subspecies: Cercopithecus pogonias pogonias (golden-bellied crowned monkey) is classified as Vulnerable (VU); C. p. elegans (Lomami River Wolf's monkey) is classified as Near Threatened (NT); C. p. nigripes (black-footed crowned monkey), C. p. grayi (Gray's crowned monkey), C. p. denti (Dent's monkey) and C. p. wolfi (Congo Basin Wolf's monkey) are classified as Least Concern (LC) on the IUCN Red List (1).

The main threats faced by the crowned guenon are habitat loss, through deforestation for timber and agricultural land, and hunting for meat. Currently, the most seriously affected subspecies is Cercopithecus pogonias pogonias, which has undergone a decline of around 30 percent since the 1980s, and may have been eliminated from certain areas. Although this subspecies is located in protected areas such as Korup National Park in north-west Cameroon, a lack of enforcement of protective measures means that poaching is common (1).