Allochrocebus solatus (Harrison, 1988)

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 : 676

58.

Sun-tailed Monkey

Allochrocebus solatus

French: Cercopitheque a queue de soleil / German: Gabun-Vollbartmeerkatze / Spanish: Cercopiteco de Gabon

Other common names: Sun-tailed Guenon

Taxonomy. Cercopithecus solatus Harrison, 1988 ,

Gabon, River Bali, Foret des Abeilles, south-east of Booué (0° 14° S, 12°15’ E).

This species is monotypic.

Distribution. C Gabon, S of the Ogooué River and W of the Offoué River, the W limit remains unclear, but it has been recorded E of the Waka National Park, the exact S limit is also unknown, butit extends to the foothills of the Massif du Chaillu. S limits may in fact be related to the presence of mountainous terrain typically avoided by this lowland forest species.

Descriptive notes. Head-body ¢.60-70 cm (males) and ¢.50-55 cm (females), tail 65-76 cm (males) and 60-67 cm (females); weight 6-9 kg (males) and 3-5—4-5 kg (females). Crown and nape of the Sun-tailed Monkey are dark gray to black, with chestnut-orange speckling, and saddle is chestnut-orange, extending to flanks, shoulders, and upper thighs. Remainder of limbs is black, while upper chest and distinctive throat ruff are notably white. Tail is bright orange-yellow toward tip, and the remainderis whitish ventrally and speckled-gray dorsally. Similar to L'Hoest’s Monkey (A. lhoesti ), the Sun-tailed Monkey carries its tail held horizontally and curving downward, and then bent upward with the tip falling back down. Face is dark, with a black muzzle and agouti-gray cheek whiskers. Ears are not hidden in the crown. Scrotum is powder blue.

Habitat. Hilly moist evergreen forests, often bisected by rivers and streams. The Suntailed Monkey prefers densely shaded, tangled areas. It is a lowland forest species, with its natural habitat dominated by Gabon mahogany ( Aucoumea , Burseraceae ), the leguminous Awoura ( Julbernardia , Fabaceae ), false nutmeg ( Pycnanthus , Myristicaceae ), and Mubala-oil tree ( Pentaclethra , Fabaceae ).

Food and Feeding. The diet of the Sun-tailed Monkey is currently being studied, but it is known to contain fruits that are abundant throughout the year. It also eats seeds, grasses, small vertebrates, and insects. It occasionally raids crops from localvillages.

Breeding. Thefirst recorded birth of a Sun-tailed Monkey in captivity occurred in the early morning hours. At three days old, the infant weighed 382 g. The fur of infant Sun-tailed Monkeys is orange-streaked black, and their skin has little pigmentation. By eleven weeks of age, adult coloration begins to appear for both face and body. The interbirth intervalis just under two years.

Activity patterns. The Sun-tailed Monkey is diurnal and semi-terrestrial. As a relatively newly discovered species,its daily activity patterns are still unknown.

Movements, Home range and Social organization. Sun-tailed Monkeyslive in unimale— multifemale groups. On average, a group has c.16 adult females. They appear to have few vocalizations and lack a loud call. It is thought that their tail coloring (white underside) and white throat ruff play a role in communication in their relatively dark forest habitat. They appearto thrive well in degraded secondary forests; i.e. population numbers remain stable after light logging because of the resulting increase in dense undergrowth. Population density varies with habitat suitability and seemingly elevation. At the Makandé Field Research Station, the density of Sun-tailed Monkeys was 25 ind/km?, but it was only c¢.4 ind/km? in southern Lopé National Park.

Status and Conservation. CITES Appendix II. Classified as Vulnerable on The IUCN Red List (as Cercopithecus solatus ). The Sun-tailed Monkey is listed as Class B under the African Convention on the Conservation of Nature and Natural Resources. It was originally believed to be confined to its type locality in the Foret des Abeilles (south and west of the great bend of the Ogooué River and east of the Offoué River), but additional populations were discovered in 1994 and again in 2010, thereby extending the known distribution to ¢.18,000 km?®. The Sun-tailed Monkey was declared a “totally protected species” by the Gabonese government in 1994. Discovered in 1984, the Suntailed Monkey has become a flagship species for conservation in Gabon. Nevertheless, it continues to be hunted for its meat, despite being difficult to hunt because ofits secretive behavior. Its semi-terrestrial nature makes it vulnerable to the use of snares and dogs for hunting, butit is also killed by shotgun in growing numbers. The biggest threat to the Sun-tailed Monkey, however,is habitat loss, mainly due to logging;its type locality, the Forét des Abeilles,is largely allocated to logging concessions and is, therefore, unprotected. The Sun-tailed Monkey occurs in Lopé National Park in Gabon, and it has been seen very near the boundaries of Waka National Park and Birougou National Park. Only a small portion of the distribution of the Sun-tailed Monkey is in Lopé National Park, while the rest occurs in unprotected areas. Thus, better protection of its habitat is recommended. Monitoring of planned logging activity and better enforcement of hunting in the area are also urgently needed. Several Sun-tailed Monkeys are held in captivity in the Centre International de Recherches Médicales de Franceville in Gabon.

Bibliography. Brugiére (2005), Brugiére & Gautier (1999), Brugiere et al. (1998), Charpentier, Deubel & Peignot (2008), Charpentier, Hossaert-McKey et al. (2005), Coad et al. (2010), Dutrillaux, Muleris & Couturier (1988), Gautier-Hion (1988), Gautier-Hion et al. (1986), Gautier et al. (2002), Groves (2001), Harrison (1988a), Kaplin (2002), Oates & Bearder (2008), Orbell et al. (1991), Peignot et al. (2002), Tooze (2011), White & Mackanga-Missandzou (1995).

Figures

49. Patas Monkey (Erythrocebus patas), 50. Grivet Monkey (Chlorocebus aethiops), 51. Tantalus Monkey (Chlorocebus tantalus), 52. Green Monkey (Chlorocebus sabaeus), 53. Malbrouck Monkey (Chlorocebus cynosuros), 54. Vervet Monkey (Chlorocebus pygerythrus), 55. Bale Mountains Monkey (Chlorocebus djamdjamensis), 56. L’Hoest’s Monkey (Allochrocebus lhoesti), 57. Preuss’s 9 Monkey Allochrocebus (null), 58. Sun-tailed Monkey (Allochrocebus solatus)

Distribution. C Gabon, S of the Ogooué River and W of the Offoué River, the W limit remains unclear, but it has been recorded E of the Waka National Park, the exact S limit is also unknown, butit extends to the foothills of the Massif du Chaillu. S limits may in fact be related to the presence of mountainous terrain typically avoided by this lowland forest species.