Bongo (antelope)
Bongo | |
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Western/lowland bongo at the Marwell Zoo in Hampshire, England | |
An eastern/mountain bongo at the Jacksonville, Duval County
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Artiodactyla |
Family: | Bovidae |
Subfamily: | Bovinae |
Genus: | Tragelaphus |
Species: | T. eurycerus
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Binomial name | |
Tragelaphus eurycerus (Ogilby, 1837)
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Subspecies | |
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Lowland bongo range | |
Mountain bongo range |
The bongo (Tragelaphus eurycerus) is a large, mostly
The western or lowland bongo, T. e. eurycerus, faces an ongoing population decline, and the
The eastern or mountain bongo, T. e. isaaci, of Kenya, has a coat even more vibrant than that of T. e. eurycerus. The mountain bongo is only found in the wild in a few mountain regions of central Kenya. This bongo is classified by the IUCN Antelope Specialist Group as Critically Endangered, with fewer individuals in the wild than in captivity (where it breeds readily).[4]
In 2000, the Association of Zoos and Aquariums in the USA (AZA) upgraded the bongo to a Species Survival Plan participant and in 2006 added the Bongo Restoration to Mount Kenya Project to its list of the Top Ten Wildlife Conservation Success Stories of the year. However, in 2013, it seems, these successes have been compromised by reports of possibly only 100 mountain bongos left in the wild due to logging and poaching.
Taxonomy
Phylogenetic relationships of the mountain nyala from combined analysis of all molecular data (Willows-Munro et.al. 2005) |
The
Bongos are further classified into two subspecies: T. e. eurycerus, the lowland or western bongo, and the far rarer T. e. isaaci, the mountain or eastern bongo, restricted to the mountains of Kenya only. The eastern bongo is larger and heavier than the western bongo. Two other subspecies are described from West and Central Africa, but taxonomic clarification is required. They have been observed to live up to 19 years.[9]
Appearance
Bongos are one of the largest of the forest antelopes. In addition to the deep chestnut colour of their coats, they have bright white stripes on their sides to help with camouflage.
Adults of both sexes are similar in size. Adult height is about 1.1 to 1.3 m (3.6 to 4.3 ft) at the shoulder and length is 2.15 to 3.15 m (7.1 to 10.3 ft), including a tail of 45–65 cm (18–26 in). Females weigh around 150–235 kg (331–518 lb), while males weigh about 220–405 kg (485–893 lb). Its large size puts it as the third-largest in the Bovidae tribe of Strepsicerotini, behind both the common and greater eland by about 300 kg (660 lb), and above the greater kudu by about 40 kg (88 lb).[10][11]
Both sexes have heavy spiral horns; those of the male are longer and more massive. All bongos in captivity are from the isolated
Coat and body
The bongo sports a bright auburn or chestnut coat, with the neck, chest, and legs generally darker than the rest of the body, especially in males. Coats of male bongos become darker as they age until they reach a dark mahogany-brown colour. Coats of female bongos are usually more brightly coloured than those of males. The eastern bongo is darker in color than the western and this is especially pronounced in older males which tend to be chestnut brown, especially on the forepart of their bodies.
The smooth coat is marked with 10–15 vertical white-yellow stripes, spread along the back from the base of the neck to the rump. The number of stripes on each side is rarely the same. It also has a short, bristly, brown ridge of dorsal hair from the shoulder to the rump; the white stripes run into this ridge.
A white chevron appears between the eyes, with two large white spots on each cheek. Another white chevron occurs where the neck meets the chest. Bongos have no special secretion glands, so rely likely less on scent to find one another than do other similar antelopes. The lips of a bongo are white, topped with a black muzzle.
Horns
Bongos have two heavy and slightly spiralled
. The horns of bongos twist once.Unlike deer, which have branched antlers shed annually, bongos and other antelopes have unbranched horns they keep throughout their lives.
Like all other horns of antelopes, the core of a bongo's horn is hollow and the outer layer of the horn is made of keratin, the same material that makes up human fingernails, toenails, and hair. The bongo runs gracefully and at full speed through even the thickest tangles of lianas, laying its heavy spiralled horns on its back so the brush cannot impede its flight. Bongos are hunted for their horns by humans.[12]
Social organization and behavior
Like other forest
Although mostly
When in distress, the bongo emits a
The calves grow rapidly and can soon accompany their mothers in the nursery herds. Their horns grow rapidly and begin to show in 3.5 months. They are weaned after six months and reach sexual maturity at about 20 months.
Ecology
Distribution and habitat
Bongos are found in
Historically, bongos are found in three disjunct parts of Africa: East, Central, and West. Today, all three populations' ranges have shrunk in size due to habitat loss for agriculture and uncontrolled timber cutting, as well as hunting for meat.
Bongos favour disturbed forest mosaics that provide fresh, low-level green vegetation. Such habitats may be promoted by heavy browsing by
Diet
Like many forest
.Bongos require
Suitable habitats for bongos must have permanent water available.[18] As a large animal, the bongo requires an ample amount of food, and is restricted to areas with abundant year-round growth of herbs and low shrubs.
Population and conservation
Few estimates of population density are available. Assuming average population densities of 0.25 animals per km2 in regions where it is known to be common or abundant, and 0.02 per km2 elsewhere, and with a total area of occupancy of 327,000 km2, a total population estimate of around 28,000 is suggested. Only about 60% are in protected areas, suggesting the actual numbers of the lowland subspecies may only be in the low tens of thousands. In Kenya, their numbers have declined significantly and on Mount Kenya, they were extirpated within the last decade due to illegal hunting with dogs. Although information on their status in the wild is lacking, lowland bongos are not presently considered endangered.
Bongos are susceptible to diseases such as
Although bongos are quite easy for humans to catch using snares, many people native to the bongos' habitat believed that if they ate or touched bongo, they would have spasms similar to
Zoo programmes
An international studbook is maintained to help manage animals held in captivity. Because of its bright colour, it is very popular in zoos and private collections. In North America, over 400 individuals are thought to be held, a population that probably exceeds that of the mountain bongo in the wild.
In 2000, the Association of Zoos and Aquariums (AZA) upgraded the bongo to a Species Survival Plan participant, which works to improve the genetic diversity of managed animal populations. The target population for participating zoos and private collections in North America is 250 animals. Through the efforts of zoos in North America, a reintroduction to the population in Kenya is being developed.
At least one collaborative effort for reintroduction between North American wildlife facilities has already been carried out. In 2004, 18 eastern bongos born in North American zoos gathered at White Oak Conservation in Yulee, Florida for release in Kenya. White Oak staff members traveled with the bongos to a Mount Kenya holding facility, where they stayed until being reintroduced.[20]
Conservation
In the last few decades, a rapid decline in the numbers of wild mountain bongo has occurred due to poaching and human pressure on their habitat, with local extinctions reported in
The Bongo Surveillance Programme, working alongside the
Animal populations with impoverished genetic diversity are inherently less able to adapt to changes in their environments (such as climate change, disease outbreaks, habitat change, etc.). The isolation of the four remaining small bongo populations, which themselves would appear to be in decline, means a substantial amount of genetic material is lost each generation. Whilst the population remains small, the impact of transfers will be greater, so the establishment of a "metapopulation management plan" occurs concurrently with conservation initiatives to enhance in situ population growth, and this initiative is both urgent and fundamental to the future survival of mountain bongo in the wild.
The western/lowland bongo faces an ongoing population decline as habitat destruction and hunting pressures increase with the relentless expansion of human settlement. Its long-term survival will only be assured in areas which receive active protection and management. At present, such areas comprise about 30,000 km2, and several are in countries where political stability is fragile. So, a realistic possibility exists whereby its status could decline to Threatened in the near future.
As the largest and most spectacular forest antelope, the western/lowland bongo is both an important flagship species for protected areas such as national parks, and a major trophy species which has been taken in increasing numbers in Central Africa by sport hunters during the 1990s.[21] Both of these factors are strong incentives to provide effective protection and management of populations.[22]
Trophy hunting has the potential to provide economic justification for the preservation of larger areas of bongo habitat than national parks, especially in remote regions of Central Africa, where possibilities for commercially successful tourism are very limited.[21]
The eastern/mountain bongo's survival in the wild is dependent on more effective protection of the surviving remnant populations in Kenya. If this does not occur, it will eventually become extinct in the wild. The existence of a healthy captive population of this subspecies offers the potential for its reintroduction.[23]
Groups supporting bongo conservation in Kenya
In 2004, Dr. Jake Veasey, the head of the Department of Animal Management and Conservation at Woburn Safari Park and a member of the European Association of Zoos and Aquariums Population Management Advisory Group, with the assistance of Lindsay Banks, took over responsibility for the management and coordination of the European Endangered Species Programme for the eastern bongo. This includes some 250 animals across Europe and the Middle East.
Along with the
To illustrate significance of genetic diversity loss, assume the average metapopulation size is 35 animals based on 140 animals spread across four populations (140/4=35). Assuming stable populations, these populations will lose 8% of their genetic diversity every decade. By managing all four populations as one, through strategic transfers, gene loss is reduced from 8% to 2% per decade, without any increase in bongo numbers in Kenya. By managing the European and African populations as one – by strategic exports from Europe combined with in situ transfers, gene loss is reduced to 0.72% every 100 years, with both populations remaining stable. If populations in Kenya are allowed to grow through the implementation of effective conservation, including strategic transfers, gene loss can be effectively halted in this species and its future secured in the wild.
The initial aims of the project are:
- Through faecal DNA analysis, estimate the genetic diversity of the remaining wild bongos and calculate the relatedness of the isolated wild populations.
- More accurately estimate the total population of wild bongos through faecal DNA analysis, camera trapping, and transect surveying.
- Through direct sampling, estimate the genetic diversity of the captive bongo population and calculate its relatedness with the remaining isolated wild populations.
- Collect DNA samples from western bongos to calculate the relatedness of the two subspecies.
- Fund rangers to collect the above data in Kenya, enhance the degree of protection afforded to and level of understanding of the eastern bongos' ecological needs.
- To realise such a metapopulation management plan, work with local communities is essential to reverse the decline and allow for the implementation of a transfer strategy. A substantial proportion of wild genetic diversity likely will have already been lost.
If effective protection were implemented immediately and bongo populations allowed to expand without transfers, then this would create a bigger population of genetically impoverished bongos. These animals would be less able to adapt to a dynamic environment. Whilst the population remains small, the impact of transfers will be greater. For this reason, the 'metapopulation management plan' must occur concurrently with conservation strategies to enhance in situ population growth. This initiative is both urgent and fundamental to the future survival of the mountain bongo in the wild.
In 2013, SafariCom telecommunications donated money to the Bongo Surveillance Programme[24] to try to keep tabs on what are thought to be the last 100 eastern bongos left in the wild in the Mau Eburu Forest in central Kenya, whose numbers are still declining due to logging of their habitat and illegal poaching.[25]
Mount Kenya Wildlife Conservancy runs a bongo rehabilitation program in collaboration with the Kenya Wildlife Service.[26] The Conservancy aims to prevent extinction of the bongo through breeding and release back into the wild.[27][28]
Status
The IUCN Antelope Specialist Group considers the western or lowland bongo, T. e. eurycerus, to be Lower Risk (Near Threatened)[2] and the eastern or mountain bongo, T. e. isaaci, of Kenya, to be Critically Endangered.[4] These bongos may be endangered due to human environmental interaction, as well as hunting and illegal actions towards wildlife.
References
- ^ IUCN SSC Antelope Specialist Group. (2017) [errata version of 2016 assessment]. "Tragelaphus eurycerus". IUCN Red List of Threatened Species. 2016: e.T22047A115164600. Retrieved 24 October 2020.
- ^ . Retrieved 24 October 2020.
- ^ Estes, Richard. "Bongo". www.britannica.com. Retrieved 11 March 2021.
- ^ . Retrieved 24 October 2020.
- ^ OCLC 62265494.
- ^ "Tragelaphus". Merriam-Webster.com Dictionary. Retrieved 7 February 2016.
- ^ Huffman, B. "Bongo". Ultimate Ungulate. Retrieved 7 February 2016.
- ^ "Bongo". Merriam-Webster.com Dictionary. Retrieved 7 February 2016.
- ^ a b Spinage, C.A. (1986) The Natural History of Antelopes. New York: Facts on File Publications.
- JSTOR 3503808. Archived from the original(PDF) on 1 April 2012. Retrieved 20 September 2011.
- ISBN 978-0-85112-235-9.
- ^ Walther, F. R. (1990) "Spiral-horned antelopes". In Grzimek's Encyclopedia of Mammals. S. P. Parker (ed.). New York: McGraw-Hill. Volume 5, pp. 344–359.
- ^ Estes, Richard D. (1991) The Behavior Guide to African Mammals: Including Hoofed Mammals, Carnivores, Primates. Berkeley and Los Angeles: University of California Press.
- ^ "Eastern bongo". www.zoobarcelona.cat. Retrieved 2 September 2020.
- ^ Estes, Richard (1993) The Safari Companion. Vermont: Chelsea Green Publishing Co.
- ^ "Bongo Antelope Facts and Information | SeaWorld Parks & Entertainment".
- ISBN 978-1-920544-34-8.
- ^ Nowak, Ronald (1991) M. Walker's Mammals of the World 5th ed. Vol. II. Baltimore: The Johns Hopkins University Press
- S2CID 26590186.
- ^ "Eastern Bongo". Retrieved 21 June 2013.
- ^ .
- ^ Institute of Applied Ecology (1998). "Tragelaphus eurycerus". In African Mammals Databank – A Databank for the Conservation and Management of the African Mammals Vol 1 and 2. Bruxelles: European Commission Directorate
- ^ IUCN (International Union for Conservation of Nature and Natural Resources). 2002. IUCN Red List of Threatened Species
- ^ Bongo Surveillance Programme monitoring and surveillance continues in Aberdare, Mt. kenya, Eburru and South West Mau. mountainbongo.org
- ^ Kenya's Mountain Bongo antelope under threat. BBC News. 18 April 2013
- ^ "Mount Kenya Wildlife Conservancy - Magical Kenya". Magical Kenya. Archived from the original on 13 April 2017. Retrieved 12 April 2017.
- ^ "Wildlife Rehabilitation | Mt. Kenya Wildlife Conservancy". www.animalorphanagekenya.org. Retrieved 12 April 2017.
- ^ Mulli, Thorn. "Date with the mountain bongo". The Standard. Retrieved 12 April 2017.