Beatragus hunteri
hirola
(Also: Hunter's hartebeest)

Hirola are found in the area between the Tana River in Kenya and the Juba River in Somalia. In 1963 a small population of about 20 individuals were introduced into the Tsavo East National Park from the South Garissa District. (Kingdon, 1997; Nowak, 1999)

Beatragus hunteri inhabits short-grass, seasonally arid, grasslands in dry acacia bush/scrub and forest-savannah mosaic habitats.

Suitable grazing lands change over time as they become unsuitable by the invasion of predators or large herds, drought, or over-growth of grasses. The largest known area grazed by a herd is over 100 square km. (Andanje, 2001; Kingdon, 1997)

Hirola have long legs, a long body, long face with a slightly convex forehead, and a relatively short neck. Total body length ranges from 1200 to 2050 mm, tail length from 300 to 450 mm, and height at the shoulder from 1000 to 1250 mm.

Generally a mixture of soft and coarser hairs that vary in color from sandy brown to slate grey cover the body. The ears are white with black tips and the tail is white. A white line passes across the forehead from one eye to the other creating a white emphasis around the eyes in the likeness of a mask.

The horns of both males and females are angular, curved, and slightly flared. They are ringed most of the length of the horn, and reach about 700mm in length when fully developed. (Kingdon, 1997)

In captivity, the average lifespan of hirola is 10.2 years. Lifespan in the wild is unknown (Huffman, 2001; Solomon Kyalo, pers.comm.).

Hirola cluster in harems, consisting of a territorial male, several females, and their young. Small groups of bachelor males and yearlings also occur. Hirola form larger herds ranging in size from 15 to 40 individuals to many hundreds, depending on the time of year. During this time, smaller herds often exchange individuals before breaking apart from the larger group. This exchange of individuals helps decrease the likelihood of genetic drift and inbreeding within smaller herds.

Most activity and grazing for hirola, takes place during the morning and evening hours. (Andanje, 2001; Kingdon, 1997)

Home Range

During occupancy of a region, hirola will graze an area of about 4 square km.

Preorbital gland secretions and posturing are used in male-male competition for access to females. Females are also likely to communicate their reproductive state via chemical cues.

Hirola are selective grazers, depending on short grasses. Occasionaly they have been oberserved to consume forbs. Their selectivity creates a need to follow the progress of newly sprouting grasses on the savannah and grasslands. If grasses grow too long, or if the grasses are disturbed by other grazers, they will move to another area. Early evening and morning are the times of highest intensity feeding.

Hirola are able to survive lengthy periods without drinking by avoiding energetic activities and storing fats.

Grasses eaten include Panicum infestum, Digitaria rivae, and Latipes senegalensis. Forbes eaten include Portulaca oleraceae, Commelina erecta, and Tephrosia subtriglora. (Andanje, 2001; Kingdon, 1997; Nowak, 1999)

In the Garissa area, hirola are preyed on by lions and hunting dogs, while in the Tsavo region, they are preyed on by cheetahs and lions. Hyenas and eagles prey on young soon after birth and before the mother and calf rejoin the herd. Poaching plays a role in the 'predation' of Hirola. The poachers are composed of military personal, civilians, herdsmen, and local gangs.

Hirola avoid predation by remaining in the herd, thereby relying on the vigilance of many individuals. (Kingdon, 1997)

It is likely that hirola play an important role in their habitats by influencing the growth and composition of plant communities. They also act as important prey species for large predators.

There are no known negative effects of hirola on humans.

Hirola are sometimes hunted for meat, they have suffered drastic declines as a result of overhunting in the past.

Hirola populations suffered two drastic declines during 1976-1978 and then in 1995. In 1976-1978 the population declined from 14,000 individuals to about 2,000 for unknown reasons. The second decline saw the population decrease from ~2,000 to 300, this decline was attributed to hunting by poachers, competition with cattle, and loss of habitat due to human encroachment. The natural habitat of hirola occurs in southwestern Somalia and southeastern Kenya, though the Somalian population is thought to be extinct or only occuring in small patchy groups. Hirola are considered one of the world's rarest species.

Conservation efforts have been underway for this species since 1963 when they were reported to be threatened. A small population was relocated in Tsavo East National Park and placed under protection by the park. By 1996 the population had reached 56 individuals. That same year, 35 more individuals were relocated to the park from Kenya in the operation "Hirola Now or Never" to increase the genetic diversity of the park population.

Efforts are being made to study the wild populations and to immplement community programs to educate local people about this species and how to help conserve it.

(Solomon Kyalo, pers. comm.)

Taxonomy of hirola has been a point of debate for many years. Hirola were considered a subspecies of topi in 1977, giving it the name Damaliscus lunatus hunteri, later they were given specific status as Damaliscus hunteri. Recently they were placed in their own genus, Beatragus, as B. hunteri. Hirola are in the subfamily Alcelaphinae based on DNA evidence and morphology.

(Solomon Kyalo, personal communication) (Nowak, 1999)