Duiker

A duiker /ˈdaɪkər/ is a small to medium-sized brown antelope native to sub-Saharan Africa, found in heavily wooded areas. The 22 extant species, including three sometimes considered to be subspecies of the other species, form the subfamily Cephalophinae. The subfamily Cephalophinae comprises three genera and 22 species, three of which are sometimes considered to be subspecies of the other species. The three genera include Cephalophus (15 species and three disputed taxa), Philantomba (three species), and Sylvicapra (one species). The subfamily was first described by British zoologist John Edward Gray in 1871 in Proceedings of the Zoological Society of London. The scientific name 'Cephalophinae' probably comes from the combination of the New Latin word cephal, meaning head, and the Greek word lophos, meaning crest. The common name 'duiker' comes from the Afrikaans word duik, or Dutch duiken - both mean 'to dive', which refers to the practice of the animals to frequently dive into vegetation for cover. The three disputed species in Cephalophus are Brooke's duiker (C. brookei), Ruwenzori duiker (C. rubidis), and the white-legged duiker (C. crusalbum). Considered to be a subspecies of Ogilby's duiker (C. nigrifrons), Brooke's duiker was elevated to species status by British ecologist Peter Grubb in 1998. Its status as a species was further seconded in a 2002 publication by Grubb and colleague Colin Groves. However, zoologists such as Jonathan Kingdon continue to treat it as a subspecies. The Ruwenzori duiker is generally considered to be a subspecies of the black-fronted duiker (C. nigrifrons). However, significant differences from another race of the same species, C. n. kivuensis, with which it is sympatric on the Ruwenzori mountain range, led Kingdon to suggest that it might be a different species altogether. Grubb treated the white-legged duiker as a subspecies of Ogilby's duiker in 1978, but regarded as an independent species by him and Groves after a revision in 2011. This was supported by a 2003 study. A 2001 phylogenetic study divided Cephalophus into three distinct lineages - the giant duikers, east African red duikers, and west African red duikers. Abbott's duiker (C. spadix), the bay duiker (C. dorsalis), Jentink's duiker (C. jentinki) and the yellow-backed duiker (C. silvicultor) were classified as the giant duikers. The east African red duikers include the black-fronted duiker (C. nigrifrons), Harvey's duiker (C. harveyi), red-flanked duiker (C. rufilatus), red forest duiker (C. natalensis), Ruwenzori duiker, and white-bellied duiker (C. leucogaster). The third group, the west African red duikers, comprises the black duiker (C. niger), Ogilby's duiker, Peters's duiker (C. callipygus), and Weyns's duiker (C. weynsi). However, the status of two species, Aders's duiker and zebra duiker, remained dubious. In 2012, Anne R. Johnston (of the University of Orleans) and colleagues constructed a cladogram of the subfamily Cephalophinae (duiker) based on mitochondrial analysis. Duikers are split into two groups based on their habitat - forest and bush duikers. All forest species inhabit the rainforests of sub-Saharan Africa]], while the only known bush duiker, grey common duiker occupies savannas. Duikers are very shy, elusive creatures with a fondness for dense cover; those that tend to live in more open areas, for example, are quick to disappear into thickets for protection. Because of their rarity and interspersed population, not much is known about duikers; thus, further generalizations are widely based on the most commonly studied red forest, blue, yellow-backed, and common grey duiker. In tropical rainforest zones of Africa, people nonselectively hunt duikers for their hide, meat, and horns at highly unsustainable rates. Population trends for all species of duikers, excluding the common duiker and the smallest blue duiker, are significantly decreasing; Aders' and particularly the larger duiker species such as the Jentink's and Abbott's duikers, are now considered endangered by the IUCN Red List of Threatened Species . Duikers range from the 3 kg (6.6 lb) blue duiker to the 70 kg (150 lb) yellow-backed duiker. With their bodies low to the ground and with very short horns, forest duikers are built to navigate effectively through dense rainforests and quickly dive into bushes when threatened. Since the common grey duiker lives in more open areas, such as savannas, it has longer legs and vertical horns, which allow it to run faster and for longer distances; only the males, which are more confrontational and territorial, exhibit horns. Also, duikers have well-developed preorbital glands, which resemble slits under their eyes, or in the cases of blue duikers, pedal glands on their hooves. Males use secretions from these glands to mark their territories.