The hirola (''Beatragus hunteri''), also called the Hunter's hartebeest or Hunter's antelope, is a critically endangeredantelope species found on the border between
Kenya
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and
Somalia
Somalia, , Osmanya script: ๐๐๐๐๐๐๐๐; ar, ุงูุตูู ุงู, aแนฃ-แนขลซmฤl officially the Federal Republic of SomaliaThe ''Federal Republic of Somalia'' is the country's name per Article 1 of thProvisional Constituti ...
. It was first described by the big game hunter and
zoologist
Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the animal kingdom, including the structure, embryology, evolution, classification, habits, and d ...
H.C.V. Hunter in 1888. It is the only living member of the genus ''Beatragus'', though other species are known from the fossil record. The global hirola population is estimated at 300โ500 animals and there are none in captivity.Probert, J. (2011 The Tsavo hirola: current status and future management MSc thesis. Imperial College London, UKKing, J., Craig, I., Andanje, S. and Musyoki, C. (2011) They Came, They Saw, They Counted, SWARA, 34: (2).James Probert, Ben Evans, Sam Andanje, Richard Kock and Rajan Amin. Population and habitat assessment of the Critically Endangered hirola ''Beatragus hunteri'' in Tsavo East National Park, Kenya. ''Oryx'', available on CJO2014. doi:10.1017/S0030605313000902. According to a document produced by the
International Union for Conservation of Nature
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of nat ...
"the loss of the hirola would be the first extinction of a mammalian genus on mainland Africa in modern human history".
Description
The hirola is a medium-sized antelope, tan to rufous-tawny in colour with slightly lighter under parts, predominantly white inner ears and a white tail which extends down to the hocks. It has very sharp, lyrate horns which lack a basal pedicle and are ridged along three quarters of their length. As hirola age their coat darkens towards a slate grey and the number of ridges along their horns increases. Hirola have large, dark sub-orbital glands used for marking their territories and give them the name "four-eyed antelope". They have white spectacles around their eyes and an inverted white chevron running between the eyes. The horns, hooves, udders, nostrils, lips and ear tips are black. Males and females look similar although males are slightly larger with thicker horns and darker coats.Sclater, P. L. (1889) Description of Hunter's antelope. ''Proceedings of the Zoological Society'' 1889, 372โ377.Dorst, J. and P. Dandelot. (1970) ''A Field Guide to the Larger Mammals of Africa''. Collins: London. 287.Kingdon, J. (1982) East African Mammals. ''An Atlas of Evolution in Africa''. Vol. IIID. Bovids. Academic Press: New York. 395- 746.Butynski, T. M. (2000) Independent Evaluation of Hirola antelope (Beatrugus hunteri) conservation status and conservation action in Kenya. Kenya Wildlife Service and Hirola Management Committee: Nairobi, Kenya.
Several sources have recorded precise measurements from both captive and wild hirola. The following are maximum and minimum values taken from all sources: height at the shoulder: 99โ125 cm, body weight: 73โ118 kg, head and body length: 120โ200 cm, horn length: 44โ72 cm, horn spread (greatest outside width): 15โ32 cm, tail length: 30โ45 cm, ear length: 19 cm. It is not stated whether horn length was measured direct from base to tip or along the curve of the horn. There is no data on how long hirola live in the wild but in captivity they have been known to live for 15 years.
Taxonomy
Authorities agree that the hirola belongs in the subfamily Alcelaphinae within the family Bovidae but there has been debate about the genus in which it should be placed. The Alcelaphinae contains
hartebeest
The hartebeest (; ''Alcelaphus buselaphus''), also known as kongoni or kaama, is an African antelope. It is the only member of the genus ''Alcelaphus''. Eight subspecies have been described, including two sometimes considered to be independ ...
,
wildebeest
Wildebeest ( , , ), also called gnu ( or ), are antelopes of the genus ''Connochaetes'' and native to Eastern and Southern Africa. They belong to the family Bovidae, which includes true antelopes, cattle, goats, sheep, and other even-to ...
and
topi
''Damaliscus lunatus jimela'' is a subspecies of topi, and is usually just called a topi. It is a highly social and fast type of antelope found in the savannas, semi-deserts, and floodplains of sub-Saharan Africa.
Names
The word ''tope'' o ...
,
korrigum
The korrigum (''Damaliscus lunatus korrigum''), also known as Senegal hartebeest, is a subspecies of the topi, a large African antelope.
Taxonomy
An 1822โ1824 British expedition across the Sahara to the ancient kingdom of Bornu, returned with ...
,
bontebok
The bontebok (''Damaliscus pygargus'') is an antelope found in South Africa, Lesotho and Namibia. ''D. pygargus'' has two subspecies; the nominate subspecies (''D. p. pygargus''), occurring naturally in the Fynbos and Renosterveld areas of ...
tsessebe
The common tsessebe or sassaby (''Damaliscus lunatus lunatus'') is the southern, nominate subspecies of '' Damaliscus lunatus'', although some authorities have recognised it as an independent species. It is most closely related to the Bangweulu ...
.
When it was first described the hirola was given the common name Hunter's hartebeest. Despite this it was placed in the genus ''
Damaliscus
''Damaliscus'', commonly known as tsessebes, is a genus of antelope in the family Bovidae, subfamily Alcelaphinae
The subfamily Alcelaphinae or tribe Alcelaphini of the family Bovidae contains wildebeest, hartebeest, bonteboks, and sever ...
'' with the topi and given the scientific name ''Damaliscus hunteri''. Newer theories have classified it as a subspecies of the topi (''Damaliscus lunatus hunteri'') or placed it within its own genus as ''Beatragus hunteri''.Gentry, A. W. (1990) Evolution and dispersal of African Bovidae. In: Bubenik, G. A. and Bubenik, A. B. (eds.). ''Horns, Pronghorns and Antlers''. Springer-Verlag: New York. 195โ227.Pitra, C., Kock, R., Hofmann, R. and Lieckfeldt, D. (1998) Molecular phylogeny of the critically endangered Hunterโs antelope (Beatragus hunteri, Sclater 1889). Journal of Zoological Systematics and Evolutionary Research 36: 179โ184.
Recent genetic analyses on karyotypic and mitochondrial DNA support the theory that the hirola is distinct from the topi and should be placed in its own genus. They also indicate that the hirola is in fact more closely related to '' Alcelaphus'' than to ''Damaliscus''. Placing the hirola in its own genus is further supported by behavioural observations. Neither ''Alcelaphus'' nor ''Damaliscus'' engage in flehmen, where the male tastes the urine of the female to determine oestrus. They are the only genera of bovids to have lost this behaviour. Hirola still engage in flehmen although it is less obvious than in other species.Andanje, S. A. and Goeltenboth, P. (1995) Aspects of the Ecology of the Hunter's Antelope or Hirola (''Beatrugus hunteri'', Sclater, 1889) in Tsavo East National Park, Kenya. Kenya Wildlife Service, Research and Planning Unit: Nairobi, Kenya.
The genus ''Beatragus'' originated around 3.1 million years ago and was once widespread with fossils found in
Ethiopia
Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, แขแตแฎแตแซ, รtiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the ...
,
Djibouti
Djibouti, ar, ุฌูุจูุชู ', french: link=no, Djibouti, so, Jabuuti officially the Republic of Djibouti, is a country in the Horn of Africa, bordered by Somalia to the south, Ethiopia to the southwest, Eritrea in the north, and the Red ...
,
Tanzania
Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands ...
and
South Africa
South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...
.Gentry, A. W. and Gentry, A. (1978) Fossil Bovidae (Mammalia) of Olduvai Gorge, Tanzania: Part 1. Bulletin British Museum Natural History (Geology) 29: 289โ446.
Ecology
The hirola is adapted to arid environments with annual rainfall averaging . Their habitats range from open grassland with light bush to wooded savannahs with low shrubs and scattered trees, most often on sandy soils.Bunderson, W. T. (1981) Ecological separation of wild and domestic mammals in an East African Ecosystem. Logan, USA: Utah State University. 220โ222. Despite the arid environments they inhabit, hirola appear to be able to survive independently of surface water. Andanje observed hirola drinking on only 10 occasions in 674 observations (1.5%) and all 10 observations of drinking occurred at the height of the dry season. Hirola do however favour short green grass and in 392 of 674 observations (58%) hirola were grazing on growths of short green grass around waterholes.Andanje, S. A. (2002 Factors limiting the abundance and distribution of hirola (''Beatragus hunteri'') in Kenya PhD thesis: University of Newcastle Upon Tyne, UK This association with waterholes may have led to reports that hirola are dependent on surface water.
Hirola are primarily grazers but browse may be important in the dry season.Bunderson, W. T. (1985) The Population, Distribution and Habitat Preferences of the Hunter's Antelope ''Damaliscus hunteri'' in north-east Kenya. In litt. to J. Williamson, WCMC: Cambridge, UK. 13. They favour grasses with a high leaf to stem ratio and ''Chloris'' and ''
Digitaria
''Digitaria'' is a genus of plants in the grass family native to tropical and warm temperate regions but can occur in tropical, subtropical, and cooler temperate regions as well. Common names include crabgrass, finger-grass, and fonio. They are ...
'' species are believed to be important in their diet. Kingdon does not consider the ecological requirements of the hirola unusual and in fact considers them to be more generalist than either '' Connochaetes'' spp. or ''Damaliscus''. A vet who examined the digestive tract of several hirola concluded that they were well adapted to eating dry region grasses and roughage. They feed on the dominant grasses of the region and Kingdon (1982) believes that quantity is more important than quality in the hirola's diet.
Hirola are often found in association with other species, particularly
oryx
''Oryx'' is a genus consisting of four large antelope species called oryxes. Their pelage is pale with contrasting dark markings in the face and on the legs, and their long horns are almost straight. The exception is the scimitar oryx, which ...
,
Grant's gazelle
Grant's gazelle (''Nanger granti'') is a species of gazelle distributed from northern Tanzania to South Sudan and Ethiopia, and from the Kenyan coast to Lake Victoria. Its Swahili name is ''swala granti''.Burchell's zebra and
topi
''Damaliscus lunatus jimela'' is a subspecies of topi, and is usually just called a topi. It is a highly social and fast type of antelope found in the savannas, semi-deserts, and floodplains of sub-Saharan Africa.
Names
The word ''tope'' o ...
. They avoid
Coke's hartebeest
Coke's hartebeest (''Alcelaphus buselaphus cokii'') or ''Kongoni'' is a large migratory antelope that is native to Kenya and Tanzania.
It can breed with Lelwel hartebeest to produce a hybrid known as the Kenya Highland hartebeest (''Alcelaphus ...
, buffalo and elephant.Andanje, S. A. (1997) Hirola monitoring progress report: update analysis of animal movement, location and herding. Biodiversity Conservation Unit, Kenya Wildlife Service: Nairobi, Kenya. Whilst hirola avoid direct association with livestock, they reportedly prefer the short grass in areas where livestock have grazed.
Social structure and reproduction
Female hirola give birth alone and may remain separate from the herd for up to two months, making them vulnerable to predation. Eventually the female will rejoin a nursery herd consisting of females and their young. Nursery herds number from 5 to 40 although the mean herd size is 7-9. They are usually accompanied by an adult male.
Young hirola leave the nursery herd at around nine months of age and form various temporary associations. They may gather together in mixed or single sex herds of up to three individuals; sub-adult or subordinate adult males may form bachelor herds of 2-38 individuals; female sub-adults may join an adult male and; if no other hirola are present, young hirola may attach themselves to a herd of Grant's gazelles or simply spend most of their time alone.
Adult males attempt to secure a territory on good pasture. These territories are up to and are marked with dung, secretions from the sub-orbital glands and by stamping grounds where males scrape the soil with their hooves and slash the vegetation with their horns. It has been suggested that at low population densities adult males abandon territory defence and will instead follow a nursery herd. Nursery herds do not defend a territory but do have home ranges which overlap the territories of several adult males. The size of a nursery herd's home range varies from with a mean size of .
Nursery herds are relatively stable but bachelor herds are very unstable with a fission fusion dynamic. In the 1970s hirola were observed forming aggregations of up to 300 individuals to take advantage of scarce, but spatially clumped, resources during the dry season (Bunderson, 1985). Information is lacking on male territoriality and how it relates to mating success, how and when hirola join a herd and how new herds are established (Butynski, 2000).
Hirola are seasonal breeders with young being born from September to November. Data on age of sexual maturity and gestation period are not available for wild hirola however in captivity gestation was around 7.5 months (227โ242 days) with one female mating at 1.4 years old and giving birth at 1.9 years. Another pair of hirola mated when they were 1.7 years of age. In captivity one of the main causes of mortality is wounds caused by intra-hirola aggression, including aggression between females.
Threats
The reasons for the historic decline of the hirola are not known but is likely a combination of factors including disease (particularly
rinderpest
Rinderpest (also cattle plague or steppe murrain) was an infectious viral disease of cattle, domestic buffalo, and many other species of even-toed ungulates, including gaurs, buffaloes, large antelope, deer, giraffes, wildebeests, and warthog ...
), hunting, severe drought, predation, competition for food and water from domestic livestock and habitat loss caused by
bush encroachment
Woody plant encroachment (also called bush encroachment, shrub encroachment, woody encroachment, bush thickening, or woody plant proliferation) is a natural phenomenon characterised by the increase in density of woody plants, bushes and shrubs, ...
as a result of the extirpation of elephants within its range.
This hartebeest prefers areas that are used by livestock which puts them at increased risk from diseases like
tuberculosis
Tuberculosis (TB) is an infectious disease usually caused by '' Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, i ...
. It might be vulnerable to poaching, and is also subject to the natural phenomena of
predation
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...
and
competition
Competition is a rivalry where two or more parties strive for a common goal which cannot be shared: where one's gain is the other's loss (an example of which is a zero-sum game). Competition can arise between entities such as organisms, indiv ...
with other wild herbivores, particularly
topi
''Damaliscus lunatus jimela'' is a subspecies of topi, and is usually just called a topi. It is a highly social and fast type of antelope found in the savannas, semi-deserts, and floodplains of sub-Saharan Africa.
Names
The word ''tope'' o ...
and
Coke's hartebeest
Coke's hartebeest (''Alcelaphus buselaphus cokii'') or ''Kongoni'' is a large migratory antelope that is native to Kenya and Tanzania.
It can breed with Lelwel hartebeest to produce a hybrid known as the Kenya Highland hartebeest (''Alcelaphus ...
, which the IUCN also calls 'threats'.
Population size and distribution
The hirola's natural range is an area of no more than 1,500 km2 on the Kenyan-Somali border, but there is also a translocated population in
Tsavo East National Park
Tsavo East National Park is one of the oldest and largest parks in Kenya at 13,747 square kilometres. Situated in a semi-arid area previously known as the Taru Desert it opened in April 1948, and is located near the town of Voi in the Taita- ...
. The natural population in the 1970s was likely to number 10,000โ15,000 individuals but there was an 85โ90% decline between 1983 and 1985. A survey in 1995 and 1996 estimated the population to number between 500 and 2,000 individuals with 1,300 as the most reasonable estimate. A 2010 survey estimated a population of 402โ466 hirola.
A translocated population was established in Kenya's Tsavo East National Park with translocations in 1963 and 1996 (Hofmann, 1996; Andanje & Ottichilo, 1999; Butynski, 1999; East, 1999). The 1963 translocation released 30 animals and the first survey in December 1995 concluded that there were at least 76 hirola present in Tsavo at the time. Eight months later a further 29 translocated hirola were released in to Tsavo, at least six of which were pregnant at the time (Andanje, 1997). By December 2000 the hirola population in Tsavo had returned to 77 individuals (Andanje, 2002) and by 2011 the population was estimated at 76 individuals.
In 2013, 9 individuals from 7 different herds were fitted with GPS-collars, scheduled to drop-off in June 2014, in north-eastern Kenya. This marked the first time that the species was GPS-collared in the wild. These collaring events served as a purpose to understand the basic ecology, the natural history, movements patterns and population demographics of the species.
Status and conservation
Hirola are critically endangered and their numbers continue to decline in the wild. There are between 300โ500 individuals in the wild and none currently in captivity.
Despite being one of the rarest antelopes, conservation measures for the antelope have so far been marginal. The
Arawale National Reserve
The Arawale National Reserve is a designated conservation area managed by the Garissa County in assistance with the Kenya Wildlife Service. It lies in North Eastern Province of Kenya, 77 km south of the town of Garissa. The reserve covers a ...
was created in 1973 as a small sanctuary for them, but has been left unmaintained since the 1980s. In 2005, four local communities in the Ijara District, in collaboration with Terra Nuova, established the Ishaqbini Hirola Conservancy. As of 2014, a 23 km2 predator-proof fenced sanctuary has been constructed at Ishaqbini and a founding population of 48 hirola is breeding well within the sanctuary.King, J., Craig, I., Golicha, M., Sheikh, M., Lesowapir, S., Letoiye, D., Lesimirdana, D., and Worden, J. (2014) Status of hirola in Ishaqbini community conservancy. Northern Rangelands Trust and Ishaqbini Hirola Community Conservancy, Kenya.
References
* Hirola Antelope ''Beatragus hunteri'' conservation status and conservation action in Keny