The addax (Addax nasomaculatus), also known as the white antelope and the screwhorn antelope, is an antelope of the genus Addax, that lives in the Sahara desert. It was first described by Henri de Blainville in 1816. As suggested by its alternative name, this pale antelope has long, twisted horns - typically 55 to 80 cm (22 to 31 in) in females and 70 to 85 cm (28 to 33 in) in males. Males stand from 105 to 115 cm (41 to 45 in) at the shoulder, with females at 95 to 110 cm (37 to 43 in). They are sexually dimorphic, as the females are smaller than males. The colour of the coat depends on the season - in the winter, it is greyish-brown with white hindquarters and legs, and long, brown hair on the head, neck, and shoulders; in the summer, the coat turns almost completely white or sandy blonde.
The addax mainly eats grasses and leaves of any available shrubs, leguminous herbs and bushes. These animals are well-adapted to exist in their desert habitat, as they can live without water for long periods of time. Addax form herds of five to 20 members, consisting of both males and females. They are led by the oldest female. Due to its slow movements, the antelope is an easy target for its predators: lions, humans, African wild dogs, cheetahs, spotted hyenas and leopards. Breeding season is at its peak during winter and early spring. The natural habitat of the addax are arid regions, semideserts and sandy and stony deserts.
The addax is a critically endangered species of antelope, as classified by the IUCN. Although extremely rare in its native habitat due to unregulated hunting, it is quite common in captivity. The addax was once abundant in North Africa, native to Chad, Mauritania and Niger. It is extinct in Algeria, Egypt, Libya, Sudan and Western Sahara. It has been reintroduced in Morocco and Tunisia.
Description[]
The Addax (Addax nasomaculatus) is a desert living antelope and is well adapted to its harsh habitat; the hooves are splayed to enable them to travel on sand, and these antelope produce highly concentrated urine as a method of conserving water. The short, glossy coat is a grey-brown colour in the winter, fading to almost white during the summer months. The underparts, rump, limbs, chin, lips and inside of the ears are white, as is the x-shaped blaze on the face. There is a tuft of dark hair on the forehead and the horns are long and twisted in both sexes.
Biology[]
These antelope are mainly active during the night, particularly in the hot season; in the day, they dig 'beds' into the sand under shade to avoid the heat of the desert sun, and also to shelter from sandstorms. Small nomadic herds spend most of their time wandering in search of food; these previously numbered around 20 individuals but today groups are only two to four strong and lone individuals are also seen. When the population was more abundant, these antelope migrated seasonally between the Sahara and the Sahel and aggregations of 1,000 individuals were seen. The herds are led by a dominant male and breeding can occur all year round. Males defend territories and mate with more than one female. Usually a single young is born and is fully weaned at around a month old. In captivity, addax can live up to 25 years. Addax feed on desert grasses, but will also browse on herbs and acacia species if grass is unavailable. Addax are able to obtain all the water they need from their food and their range is therefore not generally restricted by available water sources.
Range and Habitat[]
Once found across northern Africa, on both sides of the Sahara, from the west to the east. Addax populations exist today in a mere fragment of the former range in Niger, Chad, and possibly along the border between Mali and Mauritania.
Threats and Conservation[]
The population of addax is today a mere fraction of what it once was and this dramatic decrease is mainly attributed to over-hunting. These slow-moving animals provide easy targets, particularly with motorized vehicles and automatic weapons, and their meat and leather are prized by local people. Other factors involved in the decline include desertification, drought and habitat encroachment by pastoral expansion and subsistence agriculture. It is estimated that fewer than five hundred individuals survive in the wild today, with the bulk of these lying between the Termit area of Niger and the Bodélé region of Western Chad.
The addax is listed on Appendix I of the Convention on International Trade in Endangered Species (CITES), thus prohibiting international trade. Provided effective protection is granted for the last remaining pockets of populations, it is possible that the species can increase. With this in mind, the Sahara Conservation Fund has developed a regional strategy that when implemented will protect the remaining wild populations and facilitate the recolonisation of neighbouring suitable habitats. A protected population exists in the Yotvata Hai-Bar (Wildlife Preserve) Nature Reserve in Israel, to the north of Elat. The reserve was set up in 1968 with the view to bolster populations of endangered desert species. In Niger, a vast protected area is being established in the Termit region to protect the largest remaining addax population in the wild. There are currently around 2,000 individuals in captive populations around the world and these are being used in reintroduction programmes for the species in Tunisia and Morocco.