Cephalophus niger, Gray, 1846

Don E. Wilson & Russell A. Mittermeier, 2011, Bovidae, Handbook of the Mammals of the World – Volume 2 Hoofed Mammals, Barcelona: Lynx Edicions, pp. 444-779 : 722-723

250.

Black Duiker

Cephalophus niger

French: Céphalophe noir / German: Schwarzducker / Spanish: Duiker negro

Taxonomy. Cephalophus niger Gray, 1846 ,

Guinea Coast.

This species is monotypic.

Distribution. From S Guinea to W Nigeria (W of the Niger River).

Descriptive notes. Head-body 80-100 cm, tail 9-14 cm, shoulder height 44-50 cm; weight 19-23 kg (males) and 17-26 kg (females). A heavily built duiker; the bodyis long, with short, stocky legs. Female Black Duikers are slightly larger than males.

The pelageis soft, glossy, and black or deep brownish-black in color. The hairs on the trunk are longer than in most duikers. The undersidesare slightly paler than the back, and a rusty orange patch may be present between the forelegs. The tail is short, with a bushy white tuft at the tip; the black upper surface contrasts strikingly with the white underside. The face has very little hair; it is predominantly black with a rufous-orange forehead. The coronal tuft is rich rufous and does not taper to a point, but instead is an even shock of hair. The chin, lower jaw, and throat are pale gray. The insides of the ears are whitish and the backs are black. Horns are usually present in both sexes, although they may be hidden within the coronal tuft. Straight and pointed, the horns of males may grow 7.2-9. 4 cm in length. The horns of females are much smaller (1.8-3. 1 cm); the tips are generally rounded in adult females, although they may be sharp in subadults. Dental formulais10/3,C0/1,P 3/3, M 3/3 (x2) = 32.

Habitat. The Black Duiker is very common in lowland secondary forests and farmbush (cultivated land interspersed with brushy thickets), and it is also found in riverine galleries, isolated forest patches, and semi-deciduous forests at lower densities. It is present in low numbers in the drier and more open habitat of the Dahomey Gap between Togo and Nigeria.

Food and Feeding. Highly frugivorous. Fruits typically comprise at least 88% ofthe diet, although leaves and stems, roots, blossoms, fungi, grasses, and animal matter are also consumed. The Black Duiker is presumed to be dependent on year-round fruit like many other large duikers. Fruits up to 6 cm in diameter can be swallowed or broken inside the mouth; large fruits that cannot be swallowed whole are chewed, and toughskinned fruits are excluded from the diet. Young green leaves are preferred over dry or old leaves; the diet shifts to increased frugivory during the dry season when young shoots are rare. Fruits of Alchornea cordifolia, Ficus capensis and FE vallis-choudae, Elaes guenieensis, Persea americana , and Theobroma cacao are frequently consumed, based on stomach content analysis. The latter four species are cultivated; leaves and tubers of cassava (Manihot esculenta ) are also frequently consumed. The abundance of cultivars in the diet (in 62% of 81 stomachs examined in Kumasi, Ghana) indicates that the Black Duiker forages regularly in agricultural areas. These foods (with the exception of the native FE. guineensis ) would not form the natural diet. Among native plants, the leaves of Alchornea cordifolia are eaten often. Tubers and rhizomes are dug up with the front hooves and consumed. Black Duikers consume an average of 2-3 species in a feeding bout.

Breeding. In the wild, pregnant female Black Duikers have been recorded in every month of the year, although there appears to be a birthing peak in November—January. A single estimate of gestation from a captive specimen was 126 days, although in light of the gestation periods for similarly sized duikers,this seems extremely low. The interbirth interval in captivity averages 7-5 months. Littersize is one; neonates in Ghana average 1-94 kg (range: 1:65-2: 31 kg). In captivity, birth weights are 1-42.2-18 kg. Males tend to grow faster than females. Weaning occurs at around 90 days of age (81-108 days). Captive individuals have lived for over 14 years.

Activity patterns. In captivity, Black Duikers are three times more active during daylight hours than during the night (64% of the day spent active, 24% of the night). In Ghana, the Black Duikeris crepuscular, being most active prior to sunrise and during the cool hours of the morning, and for several hours in the late afternoon and evening (from 17:00 h onward). Midday and the middle of the night are spent lying up and resting in buttresses of large trees or in dense thickets; rumination reportedly occurs at night. Near human settlements, the presence of people during the day may alter the natural rhythms and result in a more nocturnal existence.

Movements, Home range and Social organization. Generally solitary, although pairs (adult male and female, or female and offspring) and groups of three (adult male, female, and offspring) have been observed. It is unknown how permanent such associations are.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Black Duiker is common in the center ofits range ( Liberia, Ivory Coast, Ghana), but it is heavily hunted for the bushmeat trade. It is the most adaptable mid-sized duiker in West Africa, and actually appears to be more successful in areas with human disturbance. The total population is estimated at 100,000 individuals; with a general decline in numbers across its range.

Bibliography. Barnes et al. (2002), East (1999), Farst et al. (1980), Happold (1973, 1987), Hofmann & Roth (2003), IUCN/SSC Antelope Specialist Group (2008g), Kingdon (1997), Newing (2001), Walther (1990a), Weigl| (2005), Wilson (2001).

Figures

On following pages: 245. Eastern Bay Duiker (Cephalophus castaneus); 246. Jentink’s Duiker (Cephalophus jentinki); 247. Western Yellow-backed Duiker (Cephalophus silviculton; 248. Eastern Yellow-backed Duiker (Cephalophus curticeps); 249. Abbott's Duiker (Cephalophus spadix); 250. Black Duiker (Cephalophus niger); 251. Ogilby’s Duiker (Cephalophus ogilbyi); 252. White-legged Duiker (Cephalophus crusalbum): 253. Brooke's Duiker (Cephalophus brookel); 254. Peters's Duiker (Cephalophus callipygus).

Distribution. From S Guinea to W Nigeria (W of the Niger River).