|Range of the hirola|
Cobus hunteriSclater, 1889
The hirola (Beatragus hunteri), also called the Hunter's hartebeest or Hunter's antelope, is a critically endangered antelope species found on the border between Kenya and Somalia. It was first described by the big game hunter and zoologist 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 300–500 animals and there are none in captivity.    According to a document produced by the International Union for Conservation of Nature "the loss of the hirola would be the first extinction of a mammalian genus on mainland Africa in modern human history". 
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.      
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: 99–125 cm, body weight: 73–118 kg, head and body length: 120–200 cm, horn length: 44–72 cm, horn spread (greatest outside width): 15–32 cm, tail length: 30–45 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. 
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, wildebeest and topi, korrigum, bontebok, blesbok, tiang and tsessebe. 
When it was first described the hirola was given the common name Hunter's hartebeest. Despite this it was placed in the genus Damaliscus 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.    
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.  
The genus Beatragus originated around 3.1 million years ago and was once widespread with fossils found in Ethiopia, Djibouti, Tanzania and South Africa.    
The hirola is adapted to arid environments with annual rainfall averaging 300 to 600 millimetres (12 to 24 in). Their habitats range from open grassland with light bush to wooded savannahs with low shrubs and scattered trees, most often on sandy soils.  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.  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.  They favour grasses with a high leaf to stem ratio and Chloris and Digitaria 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, Grant's gazelle, Burchell's zebra and topi. They avoid Coke's hartebeest, buffalo and elephant.  Whilst hirola avoid direct association with livestock, they reportedly prefer the short grass in areas where livestock have grazed. 
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 7 square kilometres (2.7 sq mi) 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 26 to 164.7 square kilometres (10.0 to 63.6 sq mi) with a mean size of 81.5 square kilometres (31.5 sq mi). 
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 (227–242 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. 
The reasons for the historic decline of the hirola are not known but is likely a combination of factors including disease (particularly rinderpest), hunting, severe drought, predation, competition for food and water from domestic livestock and habitat loss caused by bush encroachment 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.  It might be vulnerable to poaching, and is also subject to the natural phenomena of predation and competition with other wild herbivores, particularly topi and Coke's hartebeest, which the IUCN also calls 'threats'. 
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. The natural population in the 1970s was likely to number 10,000–15,000 individuals but there was an 85–90% 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 402–466 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. 
Hirola are critically endangered and their numbers continue to decline in the wild. There are between 300–500 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 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. 
The bongo is a herbivorous, mostly nocturnal forest ungulate. Bongos are characterised by a striking reddish-brown coat, black and white markings, white-yellow stripes and long slightly spiralled horns. They are the only tragelaphid in which both sexes have horns. They have a complex social interaction and are found in African dense forest mosaics. Native to Africa, they are the third-largest antelope in the world.
The sitatunga or marshbuck is a swamp-dwelling antelope found throughout central Africa, centering on the Democratic Republic of the Congo, the Republic of the Congo, Cameroon, parts of Southern Sudan, Equatorial Guinea, Burundi, Ghana, Botswana, Rwanda, Zambia, Gabon, the Central African Republic, Tanzania, Uganda and Kenya. The sitatunga is confined to swampy and marshy habitats. Here they occur in tall and dense vegetation as well as seasonal swamps, marshy clearings in forests, riparian thickets and mangrove swamps.
The common eland, also known as the southern eland or eland antelope, is a savannah and plains antelope found in East and Southern Africa. It is a species of the family Bovidae and genus Taurotragus. An adult male is around 1.6 metres (5') tall at the shoulder and can weigh up to 942 kg (2,077 lb) with an average of 500–600 kg (1,100–1,300 lb), 340–445 kg (750–981 lb) for females). It is the second largest antelope in the world, being slightly smaller on average than the giant eland. It was scientifically described by Peter Simon Pallas in 1766.
The subfamily Alcelaphinae or tribe Alcelaphini of the family Bovidae contains wildebeest, hartebeest, bonteboks, and several similar species. Depending on the classification, there are 6–10 species placed in four genera, although Beatragus is sometimes considered a subgenus of Damaliscus, and Sigmoceros for the Lichtenstein's hartebeest.
The sable antelope is an antelope which inhabits wooded savanna in East and Southern Africa, from the south of Kenya to South Africa, with a separate population in Angola.
The common tsessebe or sassaby 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 tsessebe, sometimes also seen as a separate species, less to the topi, korrigum, coastal topi and tiang subspecies of D. lunatus, and less to the bontebok in the same genus. Common tsessebe are found in Angola, Zambia, Namibia, Botswana, Zimbabwe, Eswatini, and South Africa.
The bontebok is an antelope found in South Africa, Lesotho and Namibia. D. pygargus has two subspecies; the nominate subspecies, occurring naturally in the Fynbos and Renosterveld areas of the Western Cape, and the blesbok occurring in the Highveld.
The hartebeest, 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 independent species. A large antelope, the hartebeest stands just over 1 m at the shoulder, and has a typical head-and-body length of 200 to 250 cm. The weight ranges from 100 to 200 kg. It has a particularly elongated forehead and oddly-shaped horns, a short neck, and pointed ears. Its legs, which often have black markings, are unusually long. The coat is generally short and shiny. Coat colour varies by the subspecies, from the sandy brown of the western hartebeest to the chocolate brown of the Swayne's hartebeest. Both sexes of all subspecies have horns, with those of females being more slender. Horns can reach lengths of 45–70 cm (18–28 in). Apart from its long face, the large chest and the sharply sloping back differentiate the hartebeest from other antelopes. A conspicuous hump over the shoulders is due to the long dorsal processes of the vertebrae in this region.
The gerenuk, also known as the giraffe gazelle, is a long-necked antelope found in parts of East Africa. The sole member of the genus Litocranius, the gerenuk was first described by the naturalist Victor Brooke in 1879. It is characterised by its long, slender neck and limbs. The antelope is 80–105 centimetres tall, and weighs between 18 and 52 kilograms. Two types of colouration are clearly visible on the smooth coat: the reddish brown back or the "saddle", and the lighter flanks, fawn to buff. The horns, present only on males, are lyre-shaped. Curving backward then slightly forward, these measure 25–44 cm.
Beatragus is a genus of alcelaphine antelope. The hirola (Beatragus hunteri) is the only living representative, but a couple of extinct species are known, all from Africa.
The bohor reedbuck is an antelope native to central Africa. The animal is placed under the genus Redunca and in the family Bovidae. It was first described by German zoologist and botanist Peter Simon Pallas in 1767. The bohor reedbuck has five subspecies. The head-and-body length of this medium-sized antelope is typically between 100–135 cm (39–53 in). Males reach approximately 75–89 cm (30–35 in) at the shoulder, while females reach 69–76 cm (27–30 in). Males typically weigh 43–65 kg (95–143 lb) and females 35–45 kg (77–99 lb). This sturdily built antelope has a yellow to grayish brown coat. Only the males possess horns which measure about 25–35 cm (9.8–13.8 in) long.
The oribi is a small antelope found in eastern, southern and western Africa. The sole member of its genus, it was described by the German zoologist Eberhard August Wilhelm von Zimmermann in 1783. While this is the only member for hte genus Ourebia, eight subspecies are identified. The oribi reaches nearly 50–67 centimetres (20–26 in) at the shoulder and weighs 12–22 kilograms (26–49 lb). It possesses a slightly raised back, and long neck and limbs. The glossy, yellowish to rufous brown coat contrasts with the white chin, throat, underparts and rump. Only males possess horns; the thin, straight horns, 8–18 centimetres (3.1–7.1 in) long, are smooth at the tips and ringed at the base.
The korrigum, also known as Senegal hartebeest, is a subspecies of the topi, a large African antelope.
Damaliscus lunatus is a large African antelope of the genus Damaliscus and subfamily Alcelaphinae in the family Bovidae, with a number of recognised geographic subspecies. Some authorities have split the different populations of the species into different species, although this is seen as controversial. Common names include topi, sassaby, tiang and tsessebe
Damaliscus, commonly known as tsessebes, is a genus of antelope in the family Bovidae, subfamily Alcelaphinae, found in Africa.
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 an area of 53,324 hectares. To the west, it is bordered by the Tana River and, to the east, by the Garissa-Lamu road. In 1974, the reserve was gazetted as the only in-situ conservation site for the critically endangered Hirola population endemic to north-eastern Kenya and south-west Somalia.
The red hartebeest, also called the Cape hartebeest or Caama, is a subspecies of the hartebeest found in Southern Africa. More than 130,000 individuals live in the wild. The red hartebeest is closely related to the tsessebe and the topi.
The Ishaqbini Hirola Conservancy is a community-based conservation area located in Garissa County, Kenya. The conservancy covers approximately 72 km2. It is located along the eastern bank of the Tana River, and borders the former Tana River Primate Reserve (1976−2007).
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.
The Bangweulu tsessebe is a population and possible taxon of Damaliscus lunatus, which are large African antelopes of the grasslands. This population is presently restricted to northern Zambia in the wild, although it was recorded as occurring in neighbouring southernmost Democratic Republic of the Congo in the 1940s. Also seen as the northernmost population belonging to the nominate southern sassaby subspecies, in 2003 it was described as a new species, only to be downgraded to a subspecies a few years later. Its taxonomic status is unclear as of 2021. As an individual sassaby of this taxon cannot be clearly distinguished from populations to the south, the taxon was defined using an experimental suite of statistical techniques applied to a sample set, based on multivariate analysis, and recognised under an experimental new taxonomy. Nominate sassaby antelopes become progressively darker on average in the northern populations, and on average have a slightly thicker horns at the base of the skull, but those of northern Zambia are the darkest and with the most robust horns on average.