Lophocebus osmani

33.

Rusty-mantled Mangabey

Lophocebus osmani

French: Lophocébe d'Osman Hill / German: Rotmantelmangabe / Spanish: Mangabey de Osman Hill

Other common names: Hill's Crested Mangabey, Osman Hill's Crested Mangabey

Taxonomy. Lophocebus albigena osmani Groves, 1978,

Cameroon, Edea, 3° 30’ N, 10° 05’ E.

L. osmani was first described as a subspecies. Reviewing the taxonomy of the genus in 2007, C. P. Groves considered L. osmani to be a full species. It probably hybridizes with L. albigena in the Dja Biosphere Reserve, Cameroon. Monotypic.

Distribution. SE Nigeria (Gashaka-Gumti National Park) and WC Cameroon, from Edea Province and across the Sanaga River to the Cameroon Plateau. The distribution needs to be reassessed.

Descriptive notes. Head—body 45-73 cm (males) and 50-56 cm (females), tail 73— 100 cm (males) and 67-80 cm (females); weight 6.1-9 kg (males) and 4.7-6.5 kg (females). The Rusty-mantled Mangabey is a slender crested mangabey, with relatively long extremities and a long tail. Upper body is black with a brownish tinge, mantle is rusty-brown or tobacco-brown with the midline not much darker, and underside is yellowish-gray, with a more yellow tinge anteriorly. Arms are pale, with black hands. Crown is black, with a somewhat swept-back tuft and apparently no “horns,” as are found in the Gray-cheeked Mangabey (L. albigena) and Johnstons Mangabey (L. johnstoni). Cheeks are bright grayish-white or golden-white, and shoulder mantle is reddish brown.

Habitat. Primary and secondary tropical, semi-deciduous forest. The Rusty-mantled Mangabey seemsto occupy higher elevations at 600 m and higher, except in the Edea District on the coast to the north of the Sanaga River.

Food and Feeding. Rusty-mantled Mangabeys eat seeds—undoubtedly an important component of the diet—along with fruits, young leaves, bark, flowers, and animal prey (invertebrates and small vertebrates). Their diets and feeding behavior have not been studied in the wild.

Breeding. There is no information available for this species.

Activity patterns. Rusty-mantled Mangabeys are diurnal and arboreal.

Movements, Home range and Social organization. There is no information available for this species.

Status and Conservation. CITES Appendix II. Classified as Least Concern on The [UCN Red List (under L. albigena). The Rusty-mantled Mangabey is listed as Class B in the African Convention on the Conservation of Nature and Natural Resources. Hunting for bushmeat and habitat loss through agricultural expansion are probably its major threats. The Rusty-mantled Mangabey is the least known of the crested mangabeys, and its distribution, ecology, and conservation status need urgent assessment. It is probably now locally extinct, for example, in Takamanda National Park in Cameroon and in the Okwango Division of Cross River National Park in Nigeria. It is known to occur in Gashaka-Gumti National Park in Nigeria and Mbam-Djerem National Park in Cameroon.

Bibliography. Adanu et al. (2011), Fleagle (1999), Gautier-Hion et al. (1999), Groves (1978, 2001, 2005b, 2007a), Grubb (2006), Hill (1974), Jolly (2007), Kingdon (1997), McGraw etal. (2012), Oates (2011), Sunderland-Groves & Maisels (2003), Swedell (2011).