Cephalophus niger [Gray, 1846].

Citation: Ann. Mag. Nat. Hist., [ser. 1], 18:165.

Type locality: "Guinea Coast" (Ghana).

The taxonomic record (above) is taken from Wilson and Reeder (1993). The black duiker is is monotypic (there are no subspecies) and is included in the subgenus Cephalophorus [Gray, 1892] (Wilson, 1987; Nowak, 1991).

Typical of duikers, the legs are relatively short and the back slightly arched. Females tend to be slightly larger than males, especially with regards to weight. Body weights for black duiker are typically 15-20 kg, although considerable variation occurs in reported values. Body length is 80-100 cm, and shoulder height is about 50 cm.

As its name suggests, the pelage of the black duiker is glossy black or brownish-black in color (Happold, 1987; Kingdon, 1997). The hairs of the coat are longer than in most duikers, although this is difficult to observe on living animals as they lie smoothly against the body (Happold, 1987). The ventral pelage is slightly paler than that on the back, and there may be a rusty orange patch between the forelegs (Happold, 1973; Happold, 1987). The tail is short - approximately 12 cm in length - with a striking white underside (Happold, 1987; Kingdon, 1997).

The pelage pales on the neck, forming a pale gray "bib" around the throat and chin (Kingdon, 1997). The head is also relatively pale with a distinct brownish hue; this is especially marked in the rufous-orange tuft of hair around and between the horns (Happold, 1987; Kingdon, 1997). The backs of the ears are dark, while their inner surfaces are covered in pale gray hair (Kingdon, 1997). Kingdon (1997) describes the nostrils as "swollen". The straight, pointed horns are usually present in both sexes, although they may be hidden within the forelock (Happold, 1987; Kingdon, 1997). Horn length is given by Happold (1973) as as 8 cm; Walther (1990) reports that those of males may grow 7.5 to 17.5 cm in length, while 24 males examined by Wilson (2001) in southern Ghana had an average horn length of 8.5 cm (7.2-9.4 cm). The horns of females are much smaller: 1.8-3.1 cm long (Wilson, 2001).

Breeding appears to occur year-round, although Wilson (2001) observed a peak in births in Ghana between November and January. A single young individual was observed in Nigeria in May, suggesting that at least some births occur during the late dry season or early part of wet season (Happold, 1987). Single offspring are the rule (Wilson, 2001). Birth weights recorded by Wilson (2001) in Ghana averaged 1.94 kg (1.65-2.31 kg); similarly, at the Los Angeles Zoo neonatal weights ranged from 1.42 to 2.18 kg (Barnes et al., 2002). In both instances, there was no difference between sexes.

Most data regarding the reproduction of this species comes from studies of captive individuals. A gestation period of 126 days was recorded at the Gladys Porter Zoo (Farst et al., 1980), although in light of the gestations of other duiker species this seems rather low. The average interval between births at the Los Angeles Zoo was 7.5 months, and, as many duikers are able to conceive shortly after calving, this may be a closer representation of the gestation period (Wilson, 2001; Barnes et al., 2002).

Barnes et al. (2002) provide a detailed account of the development of this species from experiences at the Los Angeles Zoo. Within the first 8-10 days, body weight increases to 1.65-3.20 kg, and by one month the birth weight has at least doubled to 2.75-4.00 kg. Males are generally larger than females at this time. At 46 days, a male weighing 1.85 kg at birth had increased in size to 5.9 kg. At 5.5 months of age a young female (birth weight = 1.70 kg) weighed 15.40 kg, while another female (birth weight = 1.80 kg) weighed 17.25 kg after 6 months.

Hand-raised individuals at the Los Angeles Zoo are usually weaned at around 95 days of age; data from zoos in Ghana indicate a similar weaning time of 81-108 days (Wilson, 2001). Sexual maturity in females may be acheived as early as 12 months (Wilson, 2001). Captive individuals have lived for over 14 years (Weigl, 2005).

Black duikers are very common in secondary forests (Newing, 2001; Wilson, 2001). Throughout its range, this species is found primarily in lowland rainforest habitats, although individuals have been observed in riverine galleries, isolated forest patches, and semi-deciduous forests at the margins of the species' range (Happold, 1987; Wilson, 1987; Newing, 2001). Farmbush (mixed farmland and thicket) and regenerating areas of cultivation are frequently inhabited; its ability to colonize such areas allows the black duiker to persist in areas where typical forest habitats have been destroyed (Newing, 2001; Wilson, 2001).

According to Happold (1987), the black duiker is ecologically similar to Maxwell's duiker (Philantomba maxwellii), while Kingdon (1997) suggests that it may fill a niche in Upper Guinean rainforests similar to that played by Peter's duiker (Cephalophus callipygus) in Central Africa. East (1999) assumed an average population density of 2.0 animals per km² where the species is common. Known predators include the leopard and African rock python (Wilson, 2001).

Fallen fruits and flowers, leaves, shoots, roots, fungi, and herbs comprise the diet, and this species is presumed to be dependent on year-round fruit fall like many other large duikers (Happold, 1987; Kingdon, 1997). Leaves are consumed in greater quatities during the rainy season than in the dry season (Hofmann and Roth, 2003). Thirty-three species of fruit have been recorded in the diet based on stomach content analysis, with an average of 2.5-3 species being consumed per foraging bout (Wilson, 2001; Hofmann and Roth, 2003). Preferred fruit species include Alchornea cordifolia, Ficus capensis, Ficus vallis-choudae, Elaeis guineensis (oil nut palm), Persea americana (avocado), and Theobroma cacao (cocoa). Leaves and tubers of Manihot esculenta (cassava) leaves are also frequently consumed, and black duikers have been observed actively digging up the tubers using their hooves (Wilson, 2001; Hofmann and Roth, 2003). The abundance of cultivars in the diet (present in 62% of stomachs examined by Wilson, 2001, and comprising the majority of the food in a third of these) indicates that the black duiker forages regularly in cultivated areas. These foods (with the exception of the native E. guineensis) are not native, and would not form the natural diet.

The black duiker is seldom seen, and few studies have been conducted on its behavior. Happold (1973; 1987) reports that the black duiker is mostly nocturnal, while Kingdon (1997) and Newing (2001) both state that this species is diurnal. In observing five captive black duikers at the Monrovia Zoo in Liberia, Newing (2001) found 64% of the day (0630-1800 hours) was spent active, while in only 24% of the nighttime hours (1830-0600 hours) were spent up and about (n = 260 observations). After observing black duikers in the wild, Wilson (2001) suggested that the species is mostly crepuscular, foraging for several hours around sunrise and sunset, and lying up in dense thickets or in between buttress roots at night and during the heat of the day.

The black duiker is typically solitary by nature (Happold, 1987; Wilson, 2001). However, pairs are not infrequently recorded (~14% of observations); these are typically either an adult male and adult female, or a female and her young offspring (Wilson, 2001). Occasionally, an adult male may be observed in the company of a female and her offspring (Wilson, 2001). Kingdon (1997) reports that this species is territorial in the wild.

From Kindia near the Guinea/Sierra Leone border eastwards to the Niger River (Wilson, 1987). Although formerly resident in Benin, the lack of suitable habitat and high human population have severly reduced, and possibly eliminated, the black duiker in that country. This species is one of the most common duikers in Ghana (Wilson, 2001).

Countries: Benin?, Côte d'Ivoire, Ghana, Guinea, Liberia, Nigeria, Sierra Leone, Togo (IUCN SSC Antelope Specialist Group, 2008).

The black duiker is classified as least concern by the IUCN SSC Antelope Specialist Group (2008) and is not listed by CITES. The major threat to survival is continued heavy hunting for the bushmeat trade (IUCN SSC Antelope Specialist Group, 2008). However, compared to many other forest duikers, the black duiker is resilient in the face of forest destruction and conversion to farmland (Wilson, 2001; IUCN SSC Antelope Specialist Group, 2008). Current population levels are estimated at 100,000 individuals, with a general decline in numbers across its range (East, 1999).

Duiker ("DIKE-er") is Afrikaans for "diver", a name which is derived from this antelope's habit of diving into the undergrowth when alarmed. The scientific name Cephalophus niger is derived from kephale (Greek) the head and lophus (Greek) a crest, referring to the tuft on the head; and niger (Latin) black, dark coloured.

Local names

Tuba [Dyula] (Happold, 1973)

Ewi or Ewio [Akan, Ashanti, Twi, Wassaw] (Wilson, 2001)

Wi [Fanti] (Wilson, 2001)

Wio [Bron] (Wilson, 2001)

Owin or Gyame [Sifwi] (Wilson, 2001)

Gyami [Brissa] (Wilson, 2001)

Kutu [Nyima] (Wilson, 2001)

Odu [Bowiri] (Wilson, 2001)

Duiyaya [Akpafu] (Wilson, 2001)

Kedu [Lehemi] (Wilson, 2001)

Kuma or Mo [Nkonya] (Wilson, 2001)

 

French

Céphalophe noir (Kingdon, 1997)

 

German

Schwarzducker (Kingdon, 1997)

 

Spanish

Duiquer negro (Wilson, 2001)