Cercopithecus neglectus, Schlegel, 1876

Russell A. Mittermeier, Anthony B. Rylands & Don E. Wilson, 2013, Cercopithecidae, Handbook of the Mammals of the World – Volume 3 Primates, Barcelona: Lynx Edicions, pp. 550-755 : 680-681

62.

De Brazza’s Monkey

Cercopithecus neglectus

French: Cercopitheque de De Brazza / German: Brazza-Meerkatze / Spanish: Cercopiteco de Brazza

Other common names: De Brazza's Guenon, Schlegel’s Guenon

Taxonomy. Cercopithecus neglectus Schlegel, 1876 ,

Sudan, White Nile. According to E. Schwarz in 1928, probably Niam Niam or Monbottu country.

In their 1999 guide to Central African primates, A. Gautier-Hion and colleagues described C. neglectus as belonging to the lhoesti species group. In his 2001 review, C. P. Groves assigned it to its own species group. Monotypic.

Distribution. S Cameroon (from just N of the Sanaga River, between the Mbam and Djerem rivers), S Central African Republic, Equatorial Guinea, Gabon (S to the Mpassa River and its tributaries), Republic of the Congo (S to the Nambouli River in the Lefini Faunal Reserve), E to DR Congo, Uganda, Kenya in the E of the Rift Valley (Mathews Range Forest Reserve of Samburu), and SW Ethiopia, and S to NE Angola; current presence in Uganda is unknown, but it was, in the 1960s reported in Bwamba, Bukedi, and Busia districts, and its continued existence in Ethiopia is uncertain.

Descriptive notes. Head—body 54 cm (males) and 44 cm (females), tail 70 cm (males) and 59 cm (females); weight 5-5 kg (males) and 3.2-3.6 kg (females). De Brazza’s Monkey is markedly sexually dimorphic, with females being ¢.57% of the weight of males. It is a robust species, with a shorttail. Body is gray with white bands, limbs are dark, arms are black, and there is a white haunch stripe. Underside is dark. It has a black tail. Hairs on the body have a white base, with six or seven alternating bands of white and black. There is a broad orange, crescent-shaped band on its forehead, margined in black. It has a white beard and white fur around its mouth. Scrotum is blue. There are striking age differences in appearance. Newborns are yellow-brown, with yellow limbs and underside. Infants have a dark crown and median dorsal line and a brow band thatis pale yellow. Their cheeks are pale,tail is yellow, and beard is incipient. Infant’s hair is gray at the base, with yellow tips.Juveniles are agouti grayish brown, with a chestnut brow band, rump, and tail base. Occasionally, an individual retains this coloration into adulthood—the “ezrae” morph.

Habitat. Lowland and submontane tropical moist forest, swamp forest, semi-deciduous forest, and Acacia-dominated forest; primarily riparian forests, generally preferring dense vegetation nearrivers. Seasonal flooded forests are also used. De Brazza’s Monkeys sometimes enter monoculture plantations. They have been recorded at elevations of 450-1650 m. The highest known elevation recorded is an isolated group in the Mathews Range Forest Reserve of Samburu at 2200 m.

Food and Feeding. De Brazza’s Monkey is mainly frugivorous, with 33-74% of the diet comprised of fruits. Leaves (9-:0-19-5%) and animal prey—insects (5%-10%) and reptiles—also form a substantial part oftheir diet. They frequently forage on the ground, spending as much as 30% of their day on the forest floor. They have been reported eating soil.

Breeding. Sexual maturity is reached at 4-6 years. The gestation period is 5-6 months, and usually a single infant is born. Only the female looks after the young. Individuals live for up to 22 years. In captivity, infant De Brazza’s Monkeys are reported to mature faster than other guenons.

Activity patterns. De Brazza’s Monkeys are diurnal and semi-terrestrial, spending 50-70% of their time below 5 m high in the forest canopy and ¢.20% on the ground. Locomotion is quadrupedal, with associated leaping and climbing.

Movements, Home range and Social organization. De Brazza’s Monkeys are found in small family groups in Gabon, northern Congo, Bateke Plateau, and central Cameroon. In the 1980s, it was suspected that they were monogamous, a mating system that would be inconsistent with their sexual dimorphism, which would otherwise signal polygyny. It was subsequently discovered that their mating/social system ranges from facultative monogamy to male-dominant, polygynous, unimale-multifemale groups typical of other guenons. It was supposed that their marked sexual dimorphism reflected a holdover of dimorphism established earlier in their evolutionary history when the degree of polygyny was higher, and that their inclination toward small groups and monogamy was a consequence of selection toward small group size. This is possibly an anti-predator strategy, associated with the fact that they do not form polyspecific associations as do other species of Cercopithecus and are generally more inconspicuous than other forest guenons. One may also suppose that small groups are related to the abundance and dispersion of their food sources and, as such, to avoiding interspecific feeding competition. Solitary males are observed. Group sizes are 2-35 individuals. In Trans-Nzoia and West Pokot districts of western Kenya, where they are threatened with extirpation, group sizes are significantly smaller, reported to be only 2-6 individuals. Home ranges are 4-10 ha, and average daily movements are 500-530 m.

Status and Conservation. CITES Appendix II. Classified as Least Concern on The [UCN Red List. De Brazza’s Monkey is listed as Class B in the African Convention on the Conservation of Nature and Natural Resources. Although it is locally threatened by deforestation, fragmentation, hunting, and livestock grazing,it is generally common and widespread. Rates of decline are not believed to be fast enough to warrantlisting in a threatened category.

Bibliography. Allen (1925), Cords (1988), Decker (1995), Gautier-Hion (1988), Gautier-Hion & Brugiére (2005), Gautier-Hion & Michaloud (1989), Gautier-Hion et al. (1999), Gautier & Gautier-Hion (1978), Gevaerts (1992), Goodwin (2011b), Groves (2001, 2005b), Grubb et al. (2003), Kingdon (1997), Kirkevold & Crockett (1987), Kohda (1985), Leutenegger & Lubach (1987), Maisels, Bout et al. (2007), Mwenja (2006, 2007), Napier & Napier (1985), Oates (2011), Quris (1976), Schwarz (1928), Struhsaker et al. (2008), Wahome et al. (1993).

Figures

59. Dryas Monkey (Cercopithecus dryas), 60. Diana Monkey (Cercopithecus diana), 61. Roloway Monkey (Cercopithecus roloway), 62. De Brazza’s Monkey (Cercopithecus neglectus), 63. Mona Monkey (Cercopithecus mona), 64. Campbell's Monkey (Cercopithecus campbelli), 65. Lowe's Monkey (Cercopithecus lowei), 66. Crowned Monkey (Cercopithecus pogonias), 67. Wolf's Monkey (Cercopithecus wolf), 68. Dent's Monkey (Cercopithecus dent)

Distribution. S Cameroon (from just N of the Sanaga River, between the Mbam and Djerem rivers), S Central African Republic, Equatorial Guinea, Gabon (S to the Mpassa River and its tributaries), Republic of the Congo (S to the Nambouli River in the Lefini Faunal Reserve), E to DR Congo, Uganda, Kenya in the E of the Rift Valley (Mathews Range Forest Reserve of Samburu), and SW Ethiopia, and S to NE Angola; current presence in Uganda is unknown, but it was, in the 1960s reported in Bwamba, Bukedi, and Busia districts, and its continued existence in Ethiopia is uncertain.