Gerenuk

## About

A pair of female gerenuks browsing.

The gerenuk ***(Litocranus walleri)***, meaning giraffe-antelope in Somali, is a species of antelope native to the Horn of Africa. Gerenuks have a frail frame with a long neck and legs. The neck tapers to the head and the head itself appears rather small when compared to the body. its body is rectangular and marked with a dark longitudinal saddle on the animal's dorsum. The gerenuk has a white underside and white patches over its eyes and black tear ducts. Black markings are also apparent on the inner ears, framed by white fur. Similarly to many antelope species, the gerenuk is sexually dimorphic and the males of the species possess ornamental, short black, brown or grey ringed horns on their heads. The horns curve upwards and inwards, that range from lengths of 25-44cm (9.8-17.3in) and are used for display purposes exclusively. The most interesting feature of the gerenuk is their ability to transition to a bipedal stance when feeding. They do this in order to browse the nutritious leaves that grow atop of bushes. This is an extremely unique attribute seen exclusively in gerenuks among other antelopes. The species is relatively small, growing to a total body length of 1.4-1.6m (4.5-5.2ft) and weighing 29-58kg (63.88-127.75lbs)

## Diet

Gerenuks are herbivorous browsers and feed upon the high branches of a massive variety of up to 80 bush species. Gerenuks do not drink from direct water bodies, instead favouring to gain hydration from succulent plants.

## Conservation Status

About 10% of the gerenuk's population occurs inside of protected areas, including various locations in Ethiopia and Kenya. The species also likely benefits from the transition of grasslands into farmland, as thickets become apparent food sources. Despite this, the gerenuk is not without threats and is commonly a victim of deforestation. Much of gerenuk habitat is commonly harvested for the use of firewood and charcoal. Quite uniquely, war also threatens the gerenuk as range is destroyed through warfare. The presence of an infectious disease known as rinderpest, may also cause strain on the population. Because of these factors, the gerenuk is considered near-threatened by the IUCN.

## Range and Population

Gerenuk inhabit the Horn of Africa, a region in east Africa that includes the countries of Djibouti, Ethiopia, Somalia and Kenya, all of which the gerenuk inhabits (with the addition of Tanzania). The species specialises in inhabiting arid environments such as deserts and rangeland biomes such as grasslands. The gerenuk's population is unknown however has been estimated at 95,000 mature individuals in light of recent aerial surveys. Though this number may seem large, the gerenuk population is in steady decline.

## Behaviour

Male gerenuk are solitary and territorial, interacting with females only during the mating season or during their childhood with their mothers or siblings. Males will inhabit a territory of 121.406-343.983ha (300-850ac), which they will define through the use of scent marking, using a gland adjacent to the eye known as a preorbital gland. The females from small social structures of around 10 individuals, typically comprised of related individuals and their young. These groups are free to roam throughout male territories and will not be prosecuted by the territory's owner. Male offspring will soon leave the herd after being weaned, soon forming nomadic male bachelor herds until they reach full maturity, where they will establish separate territories. As vocal animals, the gerenuk emits an array of calls, including soft bleats used by mothers to communicate to their offspring, low barks when threatened and a characteristic whistle when agitated. During a meeting between two in the mating season, the female will pin her ears back and raise her snout, displaying defense and hesitation. The male will rear his head to the side, displaying his horns. If receptive, the male will then follow the female, marking her thigh with his preorbital gland, guarding her afterwards by staying close to her. He will then use his front legs or forelegs to continually kick her thighs, in an attempt to force urination. Once she does urinate, the male will sample her urine in a method known as the flehmen or lip curl test. Once the female enters estrous, the male will be able to distinguish the difference in urine, soon mating. The male will attempt to mate with as many females as he possibly can. Female gerenuks will breed only once or twice annually and they may give birth anytime throughout the year, after a 165 day gestation period. Though birthing and reproduction may occur anytime yearly, they may be dependent on the health of the region.

### Relationship with Humans

Gerenuk have been historically hunted for trophies and bushmeat for the last 200 years. This practice has been detrimental the gerenuk's already limited population and range however, the growing interest in photo-safaris and other forms of African tourism has lately favoured gerenuks, which may raise awareness for the species.

## In Captivity

Though the gerenuk cannot be found in captivity, its subspecies, known as the Southern gerenuk ***(Litocranus walleri walleri)***, is housed relatively commonly. It can be found throughout North American and German zoos including the popular; San Diego Zoo and Teirpark Berlin respectively. Unfortunately, the gerenuk has proven quite hard to breed in captivity, which may prove to be problematic for the future of the species.

## Gallery

### Sources

* IUCN Red List of Threatened Species - https://www.iucnredlist.org/species/12142/50190292
* Gerenuk | Animal Diversity Web, University of Michigan Museum of Zoology - https://animaldiversity.org/accounts/Litocranius\_walleri/
* Gerenuk | African Wildlife Foundation - https://www.awf.org/wildlife-conservation/gerenuk
* Southern Gerenuk pdf | Denver Zoo - https://denverzoo.org/wp-content/uploads/2020/04/Southern-gerenuk.pdf
* Southern Gerenuk | ZOOINSTITUTES - https://zooinstitutes.com/animals/southern-gerenuk-956/