|Common Name||Black-backed Duiker|
The bay duiker (Cephalophus dorsalis), is a forest-dwelling duiker found in Gabon, southern Cameroon and northern Congo, as well as Sierra Leone, Liberia, and the southern parts of Côte d'Ivoire, Ghana and Benin. It may be a subspecies of Ogilby's Duiker.
Bay duikers stand around 50 cm (20 in) tall at the shoulder and weigh about 20 kg (44 lb). Females are typically larger than males, and bay duikers from Central Africa (C. d. castaneus) are larger than those from West Africa (C. d. dorsalis). Both sexes are reddish-brown, with a very bold black stripe that runs along the spine from the back of the head to the tail. The legs are dark brown, and the tail is black above and white below. The underparts are the same color as the sides, but a dark stripe runs along the center-line of the belly. The reddish face has a dark blaze that extends from the nose to the top of the forehead. White spots are present above the eyes and on the lips and chin. The cheek muscles of this species are very large and powerful. Both sexes have a pair of short, spike-like horns that extend backwards from the forehead; in males, they usually grow 5-8 cm long, while the horns of females are shorter.
Reproduction and Development
Gestation period: Approximately 240 days. Litter size: 1. Weaning: 3.5 months. Sexual maturity: 18 months (for females). Life span: Up to 17 years in captivity.
There is no specific breeding season, although in Central Africa there is a peak in births in January and February. Infants are born a uniform dark brown color, and begin to acquire the bright chestnut adult coloration at 5-6 months. For the first few weeks of life, an infant will remain hidden in dense vegetation while its mother forages.
Ecology and Behavior
The bay duiker is a nocturnal species, which provides some ecological separation from similarly-sized duikers that live in the same habitat. During the day, individuals rest in dense thickets or in the buttresses of trees. Females have home ranges 0.2-0.4 km2 in size; males may range over twice that area. Population densities are typically 1·5–8·7 individuals per km2. Bay duikers are very scent-oriented, using their noses to find food, detect danger, and communicate with others of their own species through the use of preorbital gland secretions, urine, and feces. If a threat is detected, bay duikers usually freeze in position and observe; if startled, they flee with a bounding gait into dense cover.
Family group: Solitary. Diet: Primarily fruits and seeds, but also leaves, fungi, flowers, and even animal matter (invertebrates, eggs, and birds). Main Predators: Leopard
Habitat and Distribution
Tracts of moist primary forest interspersed with dense thickets in West Africa (C. d. dorsalis) and Central (equatorial) Africa (C. d. castaneus). The approximate range is depicted in the map below.