The bay duiker (Cephalophus dorsalis), also known as the black-striped duiker and the black-backed duiker, is a forest-dwelling duiker native to western and southern Africa. It was first described by British zoologist John Edward Gray in 1846. Two subspecies are identified. The bay duiker is reddish-brown and has a moderate size. Both sexes reach at the shoulder. The sexes do not vary considerably in their weights, either; the typical weight range for this duiker is . Both sexes have a pair of spiky horns, measuring . A notable feature of this duiker is the well-pronounced solid stripe of black extending from the back of the head to the tail.

The bay duiker is a nocturnal animal. It tends to remain solitary, but pairs can also be observed. The leopard is the main predator of this duiker. It mainly prefers fruits, but may also feed on animal matter such as bird eggs. Females may conceive by the age of 18 months. Breeding occurs throughout the year. Gestation lasts about 240 days, following which generally a single offspring is born. The lifespan of the bay duiker is typically 17 to 18 years.

The bay duiker prefers old-growth or primary forests. It has been historically overhunted across its range for bushmeat. The survival of the bay duiker is also threatened by human settlement and agricultural expansion due to this duiker's preference for old-growth forests, and habitat degradation. The bay duiker is, however, still a common duiker species, and is classified as near threatened by the International Union for Conservation of Nature and Natural Resources.

Taxonomy and etymology

The bay duiker was first described by British zoologist John Edward Gray in 1846. The generic name probably comes from the combination of the New Latin word , meaning head, and the Greek word lophos, meaning crest. The specific name dorsalis is a Latin word referring to the back surface of an object. The common name "duiker" comes from the Afrikaans word , or Dutch (both mean "diver") owing to the tendency of this antelope to seek cover in bushes.

A 2001 phylogenetic study divided Cephalophus into three distinct lineages: the giant duikers, east African red duikers and west African red duikers. The bay duiker was classified as a giant duiker along with the yellow-backed duiker (C. silvicultor), Abbott's duiker (C. spadix), and Jentink's duiker (C. jentinki). In 2012, Anne R. Johnston (of the University of Orleans) and colleagues constructed a cladogram of the subfamily Cephalophinae (duiker) based on mitochondrial analysis. They showed that within the "giant duiker" group, the bay duiker formed a clade with Jentink's duiker, and the zebra duiker is sister to this clade. Similarly, Abbott's duiker and the yellow-backed duiker form a clade sister to Sylvicapra. The bay duiker and Jentink's duiker probably evolved during the Pleistocene, less than 2.5 million years ago.

Although the species may be monotypic, a 2003 paper identified two subspecies of the bay duiker:

  • C. d. dorsalis <small>(Gray, 1846)</small>: western bay duiker, found in western Africa
  • C. d. castaneus <small>{Thomas, 1892)</small>: eastern bay duiker, found in central Africa

Description

thumbnail|left|An illustration of the bay duiker from The Book of Antelopes (1894) by [[Philip Sclater]]

The bay duiker is a moderately sized antelope; the typical head-and-body length is . The tail of the eastern bay duiker terminates in a white tuft. The dorsal stripe of Peters's duiker also begins at the shoulders but widens to cover the whole of the rump, as does the fainter stripe on the white-bellied duiker. The bay duiker can be easily told apart from the black-fronted duiker and Weyns's duiker, that lack stripes. may also prey on the bay duiker. An alarmed individual becomes motionless, and might leap to flee. There have been reports of the bay duiker preying on birds (without feeding on the legs and wings) and the embryo of unhatched eggs, carrion, remains of African porcupines and kusimanses, termites, beetles and ants.

Reproduction

Females may conceive by the age of eighteen months. Breeding occurs throughout the year, and no clear peaks are known. In central Africa, births peak in January and February. The survival of the bay duiker is also threatened by human settlement and agricultural expansion due to this duiker's preference for old-growth forests, and habitat degradation.

The habitat of the bay duiker has depleted to a large extent due to deforestation.