Hirola (Beatragus hunteri)

Classification

Kingdom: Animalia

  Phylum: Chordata

    Class: Mammalia

      Order: Artiodactyla

        Family: Bovidae

          Subfamily: Alcelaphinae

            Genus: Beatragus

Taxonomy

Beatragus hunteri [P.L. Sclater, 1889].  

Citation: Proc. Zool. Soc. Lond., 1889:58.

Type locality: Kenya, E bank of Tana River.

Click on the pictures above for a larger view of the photographs

General Characteristics

Body Length: 120-200 cm / 4-6.7 ft.
Shoulder Height: 100-125 cm / 3.3-4.2 ft.
Tail Length: 30-45 cm / 12-18 in.
Weight: 80-118 kg / 176-260 lb.The coat is a light sandy brown, which turns more grey in adult males.  Two white lines form a chevron between the eyes, but, unusually, this white point is directed towards the forehead, rather than down the muzzle.  These chevron lines encircle each eye, emphasizing their position instead of concealing it.  The long, thick tail is white, as are the ears, which are tipped with black.  The skin on the nape of the neck thickens considerably in mature males (as protection from a rivals horns during sparring), and folds up behind the horns in a conspicuous ridge when the ears are pricked.  The lyrate horns are much more like those of an impala than a topi or hartebeest, but are shorter and sturdier with heavy ridges along most of their length.

Ontogeny and Reproduction

Gestation Period: 7.5-8 months
Young per Birth: 1Breeding occurs at the onset of the long rainy season in March and April, with the majority of births occurring just prior to the short rains in October and November.  Young go through a brief 'lying up' phase, hiding away from their mothers.

Ecology and Behavior

Most feeding activity occurs in the early morning and evening.  Hirola are very good at storing fat, which, along with a low activity level, help this species to survive droughts.  Herds are fairly sedentary, adult males especially so.  Males holding territories often posture on 'stamping grounds' created by scraping at the dirt with their hooves and marked with dung heaps, in which head bobbing - made more conspicuous by the white ears and facial mask - plays a large part.  Scent marking of grasses with secretions from the preorbital gland is also common.  When fighting in earnest, males generally kneel in front of their opponent, while wrestling and sparring occur in an upright position.Family group: Females and their young in herds of 5-40 animals, generally led by a single territorial male.  All male groups are common, and may be associated with topi bachelor herds.
Diet: Grasses
Main Predators: Lion, hyena, cheetah.

Distribution

Arid, grassy plains bound by semi-desert inland and coastal forests on the south-eastern coast of Kenya and Somalia.

Range Map (Redrawn from IEA, 1998)

Conservation Status

Hunter's hartebeest is classified as critically endangered by the IUCN (1996), with fewer than 400 living individuals.  Counts in the 1970's estimated the hirola population to be close to 14,000 animals, but by 1983, only about 7,000 were believed to exist.  Competition with domestic cattle is thought to have played a large role in this decline, although severe drought and poaching are also factors.

Remarks

This antelope has recently become very rare, with current censuses reporting fewer than 400  individuals.  Hunter's hartebeest occupies a unique taxonomical position, with some authors classifying it as a mere subspecies of topi, while others place it in a separate genus Beatragus.  More often, however, the hirola is placed in the subgenus Beatragus, which both allies it with the topi and accentuates its uniqueness.  This species is thought to be the evolutionary link between true hartebeests and the sassabies (genus Damaliscus).  As such it is a relic species, and only exists today (barely) due to its unique habitat requirements.  Another name for this antelope is the "four-eyed antelope", due to its pronounced, dark-coloured preorbital glands, which are enlarged when excited.  H. C. V. Hunter (1861-1934), a big game hunter and zoologist, discovered this antelope in 1888 about 240 km / 150 miles up the Tana River in Kenya.