scimitar oryxThe scimitar oryx or scimitar-horned oryx, also known as Sahara oryx, is a species of Oryx now extinct in the wild. It formerly inhabited all of North Africa. It has a long taxonomic history since its discovery in 1816, by Lorenz Oken, as Oryx algazel. This spiral-horned antelope is a little more than 3.3 ft at the shoulder. The males weigh 310–460 lb and females weigh 200–310 lb. The coat is white with a red-brown chest and black markings on the forehead and down the length of the nose. The calves are born with a yellow coat, and the distinguishing marks are initially absent. The coats change to adult coloration at three to 12 months old.

The scimitar oryx formed herds of mixed sexes of up to 70 members, with the bulls usually guiding the herds. They inhabited semideserts and deserts, and were adapted to live in the extreme heat – with their efficient cooling mechanism and very low requirement of water. Scimitar oryx feed on foliage – grasses, succulent plants and plant parts, during the night or early morning. Births peak between March and October. After a gestational period of eight to nine months, one calf is born. Soon after, the female experiences a postpartum estrus.

The scimitar oryx was once widespread in northern Africa. It originally began declining due to climatic changes; later, these animals were hunted extensively for their horns. Today, they are bred in captivity in special reserves in Tunisia, Morocco and Senegal. In Ancient Egypt, the scimitar oryx was domesticated and believed to be offerings for gods and used as food. Wealthy people in Ancient Rome also bred the oryx. The use of their valuable hides began in the Medieval Age. The unicorn myth may have originated from sightings of a scimitar oryx with a broken horn.

Both males and females reach sexual maturity at 1.5 to 2 years of age. Births peak in between March and October. The frequency of matings depend upon the environmental conditions. The more favorable the conditions, the more the matings occur. Zoo males are active in autumn.

In a study, the ultrasonography and radioimmunoassay analysis of sex hormones like estradiol-17β, lutropin and progesterone and excreta was used to obtain more information about the ovarian activity in these antelopes. Maximum diameters of the ovarian follicle and corpus luteum were found to be 0.59 in and 1.3 in respectively. The progestin concentrations in the excreta corresponded with the functional corpus luteum, and was useful for monitoring luteal activities and functions better. In another study, the duration of estrous cycle was found to be roughly 24 days. The females experienced an anovulatory period in spring. Periods between births were less than 332 days, which showed that the scimitar oryx is polyestrous.

Courting is done through the means of a mating circle. The male and female stand parallel to one another facing opposite directions. They then circle around one another until the female allows the male to mount from behind. However, if the female is not ready to mate, she can run away and circle in the reverse direction. Ejaculations occur in 30 minutes of courtship.Pregnant females leave the herd for a week, give birth to the calf and reconceive during their postpartum estrus, with which it can produce a calf a year. The gestation period lasts about 9 months, after which a single offspring is born, weighing 20 to 33 pounds. In a study, there were very rare twin births – only 0.7% of the total number of births. Within hours after birth, both mothers and calves return to the main herd. The female separates herself from the herd for a few hours while she nurses the young. Weaning starts at 3.5 months. The young become fully independent at around 14 weeks of age.

Today the scimitar oryx is extinct in the wild. Previously, it inhabited grassy steppes, semideserts and deserts in a narrow strip of central north Africa (Niger and Chad). It was widespread in the fringes of the Sahara, mainly in the subdesert Great Steppe, the grassy zone between the real desert and the sahel. This area was characterized by an annual rainfall of 3.0–5.9 in. Once in 1936, a single herd of 10,000 oryx was noticed in the steppe area of Chad. By the mid-1970s, Chad housed more than 95% of the world population of this species. According to IUCN, it is regionally extinct in Algeria, Burkina Faso, Chad, Egypt, Libya, Mali, Mauritania, Morocco, Niger, Nigeria, Senegal, Sudan, Tunisia and western Sahara Desert.

Scimitar oryx were hunted for their horns, almost to extinction. Originally, it began to decline as a result of major climatic changes that caused the Sahara Desert region to become dry. The northern population was mostly lost prior to the 20th century. The decline of the southern population accelerated as Europeans began to settle the area and hunt them for meat, hides and horn-trophies. World War II and the Civil War in Chad during the 1980s are thought to have caused heavy decreases of the species through an increase in hunting for food. Roadkill, firearms for easy hunting and nomadic settlements near waterholes (their dry-season feeding places) have also decreased numbers.

Where once they occupied the whole Sahara Desert, they are now considered to be extinct in the wild, with no confirmed sightings in the wild. Reports of sightings in Chad and Niger remain unsubstantiated, despite extensive surveys carried out throughout Chad and Niger in 2001–2004 in an effort to detect Sahelo-Sahara antelopes. At least until 1985, 500 oryx were estimated to be surviving in Chad and Niger, but by 1988, only a few individuals survived in the wild.

The scimitar oryx is now under a global captive breeding program. In 2005, at least 1,550 captives were managed as part of breeding programmes, and more than 4,000 are believed to be held in private collections in the United Arab Emirates. Fenced in herds in Bou Hedma National Park (1985), Sidi Toui National Park (1999) and Oued Dekouk National Park (1999) in Tunisia; Souss-Massa National Park (1995) in Morocco; Ferlo Faunal Reserve (1998) and Guembuel Wildlife Reserve (1999) in Senegal are part of the reintroduction plans.

A female calf was born in the Smithsonian Conservation Biology Institute of the National Zoo in Front Royal, Virginia on April 16, 2010, increasing the Smithsonian’s herd to 17.