Hirola

The hirola (Beatragus hunteri), Hunter's hartebeest or Hunter's antelope, is a critically endangered antelope species found on the border between Kenya and Somalia. They were discovered by Kenyans living in the area in 1888 It is the only extant member of the genus Beatragus. The global hirola population is estimated at 300–500 animals, there are no hirola in captivity and the wild population continues to decline. According to the International Union for Conservation of Nature Red List '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 hirola in captivity 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 sub-species of the topi (Damaliscus lunatus hunteri) and 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 Alcelaphalus than to Damaliscus.Placing the hirola in its own genus is further supported by behavioural observations. Neither Alcelaphalus 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 now the only extant member of the genus and is ranked forty third on the Zoological Society of London's (ZSL) list of Evolutionary Distinct and Globally Endangered (EDGE) species. 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 has led to false reports that hirola are dependent on surface water.