Kobus ellipsiprymnus ssp. defassa
|Scientific Name:||Kobus ellipsiprymnus ssp. defassa (Rüppell, 1835)|
|Taxonomic Notes:||Defassa Waterbuck (Kobus ellipsiprymnus defassa) is one of two subspecies of Waterbuck recognized (formerly regarded as distinct species); the other being Common Waterbuck (K. e. ellipsiprymnus). Lorenzen et al. (2006) found a high degree of genetic differentiation between the subspecies and strongly confirmed hybridization in Kenya’s Nairobi National Park (N.P.) population.|
|Red List Category & Criteria:||Near Threatened ver 3.1|
|Assessor(s):||IUCN SSC Antelope Specialist Group|
Numbers of this subspecies were estimated at 95,000 in 1999, with about 60% in protected areas. However, declines have been reported within many protected areas in its range, such that it is suspected that a decline of 20-25% over the course of three generations (21 years) may have taken place. Almost qualifies for listing as Vulnerable under criterion A2.
|Previously published Red List assessments:|
|Range Description:||The Defassa Waterbuck (Kobus ellipsiprymnus defassa) is found west of the western Rift Valley and south of the Sahel from Eritrea in the east to Guinea Bissau in the west; its most northerly point of distribution is in southern Mali (Spinage 2013). A population still exists in Niokola-Koba in Senegal and these individuals may range into the Gambia (where the resident population became extinct around 1990) (Spinage 2013). Defassa Waterbuck also range east of the Congo Basin forest, spreading west below the basin’s southern limit through Zambia into Angola. Another branch of the distribution extends northwards, west to the Congo River in Congo Republic.|
For the distribution map, see the parent species assessment: Kobus ellipsiprymnus.
Native:Angola (Angola); Benin; Burkina Faso; Burundi; Cameroon; Central African Republic; Chad; Congo; Congo, The Democratic Republic of the; Côte d'Ivoire; Eritrea; Ethiopia; Gabon; Ghana; Guinea; Guinea-Bissau; Kenya; Mali; Niger; Nigeria; Rwanda; Senegal; Sierra Leone; South Sudan; Sudan; Tanzania, United Republic of; Togo; Uganda; Zambia
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||East (1999) produced a global population of approximately 95,000 Defassa Waterbuck (a conservative, corrected continent-wide estimate based mainly on aerial surveys). No recent global population estimate is available. The overall population trend is decreasing.|
Typical density estimates obtained by aerial surveys of areas where the species is reasonably common are of the order 0.05-0.15/km². Ground surveys have provided density estimates of the order 0.4-1.5/km² in areas where the species is common.
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||Defassa Waterbuck inhabits savanna woodlands and forest-savanna mosaics near permanent water (East 1999). Defassa Waterbuck are generally limited to areas receiving at least 750 mm annual rainfall (Spinage 2013). This subspecies has been recorded to at least 2,100 m in Ethiopia, and perhaps to 3,000 m (Yalden et al. 1996). Waterbuck are able to exploit a range of habitats to which its congeners are specifically adapted, albeit only to a varying degree, being not as aquatic as the Lechwe, nor as independent of water as the Kob (Spinage 2013). Waterbuck are classified as grazers, but also browse.|
|Generation Length (years):||7.1|
|Use and Trade:||Waterbuck are hunted for food and sport and are particularly susceptible due to their sedentary nature and fondness for cultivation (Spinage 2013).|
|Major Threat(s):||Defassa Waterbuck have been eliminated widely within their former range mainly due to hunting (Spinage 2013). Even though they remain well represented in protected areas, several populations of Defassa Waterbuck have undergone steep declines, including those in Queen Elizabeth N.P., Murschison Falls N.P., Akagera N.P., and Comoé N.P. (Spinage 2013, and references therein).|
|Conservation Actions:||Around 60% of Defassa Waterbuck occur in protected areas (East 1999). Important populations include: Niokolo-Koba (Senegal), Comoé (Côte d'Ivoire), Arly-Singou and Nazinga (Burkina Faso), Mole and Bui (Ghana), Pendjari (Benin), the national parks and hunting zones of North Province (Cameroon), Manovo-Gounda-St. Floris (Central African Republic), Moukalaba (Gabon), Garamba and Virunga (Congo-Kinshasa), the Awash Valley and Omo-Mago-Murule (Ethiopia), Murchison Falls and Queen Elizabeth National Parks (Uganda), Serengeti and Katavi-Rukwa (Tanzania) and Kafue (Zambia), but many of these populations are in decline because of poaching (East 1999).|
East, R. (compiler). 1999. African Antelope Database 1998. IUCN, Gland, Switzerland and Cambridge, UK.
IUCN. 2017. The IUCN Red List of Threatened Species. Version 2017-2. Available at: www.iucnredlist.org. (Accessed: 14 September 2017).
Lorenzen, E.D., Simonsen, B.T., Kat, P.W., Arctander, P. and Siegismund, H.R. 2006. Hybridization between subspecies of waterbuck (Kobus ellipsiprymnus) in zones of overlap with limited introgression. Molecular Ecology 15: 3787-3799.
Spinage, C.A. 2013. Kobus ellipsiprymnus Waterbuck. In: J. Kingdon & M. Hoffmann (ed.), The Mammals of Africa. VI. Pigs, Hippopotamuses, Chevrotain, Giraffes, Deer, and Bovids, pp. 461-468. Bloomsbury Publishing, London, UK.
Yalden, D.W., Largen, M.J., Kock, D. and Hillman, J.C. 1996. Catalogue of the Mammals of Ethiopia and Eritrea. 7. Revised checklist, zoogeography and conservation. Tropical Zoology 9(1): 73-164.
|Citation:||IUCN SSC Antelope Specialist Group. 2017. Kobus ellipsiprymnus ssp. defassa. The IUCN Red List of Threatened Species 2017: e.T11040A50190098.Downloaded on 22 February 2018.|