White antelope, Screwhorn antelope
The addax (Addax nasomaculatus) is an antelope native to the Sahara Desert. The only member of the genus Addax, it was first described scientifically by Henri de Blainville in 1816. Addax are well-adapted to exist in their desert habitat, as they can live without water for long periods of time. Although extremely rare in their native habitat due to unregulated hunting, addax are quite common in captivity. They were once abundant in North Africa but currently are only native to a few countries. They are extirpated from Algeria, Egypt, Libya, Sudan, and Western Sahara, but have been reintroduced into Morocco and Tunisia.
The addax is a spiral-horned antelope. The horns, which are found on both males and females, have two to three twists and are typically 55-80 cm (22-31 in) in females and 70-85 cm (28-33 in) in males, although the maximum recorded length is 109.2 cm (43.0 in). The lower and middle portions of the horns are marked with a series of 30 to 35 ring-shaped ridges. The coloring of the addax's coat varies with 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. Their head is marked with brown or black patches that form an 'X' over their noses. They have scraggly beards and prominent red nostrils. Long, black hairs stick out between their curved and spiraling horns, ending in a short mane on the neck. The tail is short and slender, ending in a puff of black hair. The hooves are broad with flat soles and strong dewclaws to help them walk on soft sand. All four feet possess scent glands. The females of this species are smaller than the males.
Found across northern Africa in the past, on both the west and east sides of the Sahara, today addax populations exist in just a fragment of their former range in Chad, Niger, and possibly along the Mali - Mauritania border. These animals inhabit semi-deserts, arid regions, and stony and sandy deserts. They can occur in extremely arid regions that have less than 100 mm of rainfall per year. They also live in deserts where tussock grasses and the succulent thorn scrub cornulaca grow.
Addax are active mainly during the night, especially in the hot season; during the day, they will dig 'beds' under shade into the sand to avoid the desert sun’s heat and to shelter from sandstorms. Individual addax can live some distance from one another in their habitat without causing any problems because of their sensory skills whereby they can detect and find each other over huge distances. They are also able to track rainfall, heading for rainy areas where there is more vegetation. Some addax live with others in herds of 5-20 individuals of males and females. The herds usually stay in one place, though they may wonder when searching for food. The eldest dominant male usually leads the herd. Females establish a dominant hierarchy, with the oldest animals having the highest ranking. Addax are known as "short leg" runners and cannot run very fast, so fall prey to predators who are faster.
Addax are herbivores (graminivores, folivores) and eat grasses and leaves of shrubs, leguminous herbs, and bushes are available. They will also browse the leaves of Acacia trees in the absence of these grasses
Addax exhibit polygynous mating behavior. Males try to establish a territory of their own, attempting to keep breeding females inside the boundaries. A male will mate with a number of females in his territory. Year-round breeding occurs, with birth peaks in early spring and winter. Gestation lasts for 257-264 days, with one young being almost always the case. The calf is hidden for about the first 6 weeks and its mother suckles it 2-3 times each day. It is weaned at 23-39 weeks. Males are reproductively mature by about 24 months, and females at the time of the second or third summer.
Addax are slow-running, heavily built antelopes and so are easy prey for people with modern weapons. Many resident populations have been decreased or eliminated by hunting in many parts of this animal’s original range. Four-wheel-drive vehicles with tourists also affect addax by chasing them to the point of exhaustion and death. Recent droughts, increasing human population, and desertification of savanna lands have all contributed to decreasing addax populations.
According to the IUCN Red List, the total addax population size is around 30-90 mature individuals. Currently, this species is classified as Critically Endangered (CR) and its numbers today are decreasing.
