Bongo (Tragelaphus eurycerus)

KingdomAnimalia
PhylumChordata
ClassMammalia
OrderCetartiodactyla
FamilyBovidae
GenusTragelaphus (1)
SizeBody length: 170 - 250 cm (2)
Tail length: 45 - 65 cm (2)
Shoulder height: 110 - 130 cm (2)
Female weight: 210 - 235 kg (3)
Male weight: 240 - 405 kg (3)

Classified as Near Threatened (NT) on the IUCN Red List (1), and listed on Appendix III of CITES in Denmark (4). Subspecies: the western bongo (T. e. eurycerus) is classified as Near Threatened (NT), and the eastern bongo, or mountain bongo, (T. e. isaaci) as Critically Endangered (CR) on the IUCN Red List (1).

This striking species is the largest and most colourful of all African antelope, immediately recognisable by its rich chestnut-red coat (3), conspicuously striped with 10 to 15 thin, white vertical lines on the torso and rump (2) (5). Equally impressive are the bongo’s long, spiralling horns, which reach up to around a metre in length (3) (5). Although the sexes are similar in appearance, males are larger than females and their coat darkens with age, eventually becoming brownish-black, and females tend to possess longer, thinner and more parallel horns than males (2) (3). Both sexes possess a crest of hair that runs the length of the back and the legs are boldly patterned with chestnut, black, and white (2) (6). Other notable features include large ears, a conspicuous white chevron between the eyes, two large white spots on each cheek and a whitish collar at the base of the neck (2) (6). The eastern bongo is larger than its West African counterpart (6).

Found from West Africa and the Congo Basin to the Central African Republic and southern Sudan (6), with small isolated populations of the eastern or mountain bongo (T. e. isaaci) in Kenya. The mountain bongo used to occur in the Mau Forest and Mount Kenya National Park, but is now believed to be extinct in these areas. A few remain in the Aberdares Conservation Area (7).

The bongo predominantly inhabits lowland forests across most of its range, although it is found up to an altitude of 4,000 metres in the montane forest regions of East Africa, usually in tropical rainforest with dense undergrowth (2) (3) (6).

Bongos typically live in small family groups of up to eight females, their young, and a dominant male (5), although larger ‘nursery’ groups often aggregate after the calving period and mixed-sex groups of up to 50 have been observed (8). Surplus males are usually solitary, although they may be accompanied by a younger bull (8). Most active at dawn and dusk (8), these shy, reclusive animals forage within the bushes and shrubs of the forest during the day, and only come out to the salt licks during the night (3). The diet includes a range of grasses, herbs, leaves, flowers, twigs, thistles and cereals (3). Individuals use their long, prehensile tongue for grasping leaves and pulling up roots and grasses, while their broad horns are used for pulling and breaking high branches (3) (5).

Females typically give birth to a single calf after a nine month gestation period (5) (8). For a short period after birth calves are left alone, lying still in a sheltered spot to avoid detection by predators, with the mother periodically returning to nurse the calf (2). Young are weaned at six months, and become sexually mature at around 20 months of age (2) (7).

Poaching and illegal trapping for food and skins, combined with habitat destruction, have resulted in the decline of bongo populations (3) (8), and even their complete elimination in some areas (6). Large scale and unrestricted hunting with dogs and snares has had a particularly strong impact on the eastern bongo subspecies (6), which, together with lion predation and an outbreak of rinderpest in the 1980s, has decimated the wild population, leaving a mere 100 estimated individuals remaining (5) (8).

Fortunately, there has been concerted conservation effort over recent decades to help protect the endangered eastern bongo subspecies. Remaining wild bongos are currently fully protected by the Kenyan Wildlife Service, and in an attempt to protect the dwindling Aberdares population, the Park Service culled 200 lions from the Aberdares Conservation Area in April 2000 (5). A robust captive population of 526 individuals (as of December 2003) flourishes in over one hundred locations around the world, and captive stock have now begun to be used in a crucial and collaborative reintroduction project known as the Bongo Repatriation Program (5) (8). In January 2004, the first captive stock was moved from America to Mount Kenya Wildlife Conservancy, where the animals form a core breeding group, producing offspring that will eventually be released into the Mount Kenya World Heritage Site (5). In 2006, the entire herd at the Conservancy numbered 36, and three additional adult males were released on Mount Kenya (9). The success of the reintroduction of the above specimens into the wild is currently uncertain. However, while the future of the wild eastern bongo still remains uncertain, the healthy captive population is sure to play a key role in the fate of this subspecies, by providing a reservoir of animals that could be reintroduced into the wild, where they truly belong (5).

For more information on the bongo and the Bongo Repatriation Program see:

Authenticated (03/09/07) by Dr David Mallon, Co-chair of IUCN/SSC Antelope Specialist Group.

  1. IUCN Red List (June, 2009)
    http://www.iucnredlist.org
  2. The Ultimate Ungulate Page (August, 2006)
    http://www.ultimateungulate.com/Artiodactyla/Tragelaphus_eurycerus.html
  3. Animal Diversity Web (August, 2006)
    http://animaldiversity.ummz.umich.edu/site/accounts/information/Tragelaphus_eurycerus.html
  4. CITES (August, 2006)
    http://www.cites.org
  5. Rare Species Conservatory Foundation (August, 2006)
    http://www.rarespecies.org/bongo.html
  6. African Wildlife Foundation (August, 2006)
    http://www.awf.org/wildlives/63
  7. Mallon, D. (2007) Pers. comm.
  8. International Studbook of Bongo Antelope (Tragelaphus eurycerus isaaci) 2003, Volume XVIII (August, 2006)
    http://library.sandiegozoo.org/studbooks/ungulates/bongoantelope2003.pdf
  9. Mount Kenya Wildlife Conservancy (August, 2006)
    http://www.animalorphanagekenya.com/bongo_repatriation.php