Oryx are mostly white with reddish brown necks and marks on the face and a long, dark, tufted tail. The white coat helps reflect the heat of the desert. Their black skin and tip of the tongue protects against sunburn while enlarged hooves enable the oryx to walk easily on sand. Dense eyelashes and strong eyelids protect against windblown sand.
Both male and female scimitar-horned oryx have long, ridged, sharp-tipped and curved backwards horns that grow to be several feet long.
Scimitar-horned oryx have an interesting way of coping with a shortage of water. They are able to tolerate a rise in body temperature by several degrees. Being able to tolerate an internal body temperature of 116 degrees Fahrenheit means oryx do not need to sweat as much, which in turn conserves water. This adaptive hyperthermia allows them to rid themselves of excess heat at night when their body temperatures can drop below normal.
In addition to this physiological adaptation to hot and arid environments, they can go for long periods without drinking water. They dissipate heat through their appendages.
These desert antelope stand up to 4.6 feet (1.4 meters) tall at the shoulder, and their head and body length is between 4.9 to 7.5 feet (1.5 and 2.3 meters). They weigh between 220 to 460 pounds (100 and 210 kilograms).
A century ago, hundreds of thousands of desert-adapted antelopes roamed the Sahara and Sahel regions of Northern Africa, a vast desert and sub-desert ecosystem that include parts of Morocco, Tunisia, Algeria, Libya, Egypt, Mauritania, Mali, Niger, Chad and Sudan.
Due to human disturbance, over-hunting, drought and loss of food because of excessive livestock grazing, the scimitar-horned oryx is now extinct in the wild, though surveys show that Niger and Chad may have appropriate habitat for reintroduction, and some reintroductions have begun in Tunisia.
Arid-land antelope, unlike livestock, are well suited for their habitat, surviving for months and even years without drinking water, stripping moisture from the plants they eat in their sparsely vegetated habitats. Scimitar-horned oryx migrate enormous distances searching for fresh grazing and water. They can detect slight variation in air humidity over long distances.
Scimitar-horned oryx eat grasses, herbs, juicy roots, and buds. Acacia seedpods provide important nutrients for mothers with young calves. Wild melon and the twigs and shoots of Capparis are vital sources of moisture. Feeding at night allows oryx to take advantage of higher water content in their forage. They produce very dry fecal pellets and highly concentrated urine.
The Smithsonian's National Zoo's oryx eat herbivore pellets and orchard grass hay. For enrichment, the oryx also get varying browse, a variety of flavored hays and puzzle feeders with food inside.
About 8 to 8.5 months after mating, females give birth to a single calf weighing about 22 pounds (10 kilograms).
Scimitar-horned oryx become inactive in the heat of the day, seek shade and dig out scrapes in the sand to reduce exposure to drying winds. They graze primarily at night.
The life span of oryx in the wild is unknown, but in human care it is possible for them to live into their twenties.
Scimitar-horned oryx are extinct in the wild. The last photo of oryx in the wild was in 1980 in Aïr Mountains in Niger. In 1996, oryx were given the status of Critically Endangered based on unconfirmed reports that a few animals survived in the wild in Chad. No definite evidence of its survival in the wild was ever obtained however so their IUCN Red List status was changed to Extinct in the Wild.
Some contributing factors to the extinction of scimitar-horned oryx include prolonged drought, desertification and loss of pasture, human encroachment on their habitat for agriculture, shift from subsistence to commercial hunting, civil war and unrest, and excessive domestic livestock grazing on limited vegetation.
Tunisia currently leads the way in terms of concerted actions for scimitar-horned oryx. The country has expressed a commitment to re-establish the oryx as a participant in the Convention on Migratory Species Action Plan for the Conservation and Restoration of Sahelo-Sahara Antelopes and has developed a national strategy to achieve this.
The Zoo has partnered with the Sahara Conservation Fund, an independent nonprofit organization, and other zoos to establish a master plan for the re-introduction of oryx across the Saharan range, their native home. Poaching and human conflict primarily contributed to the species' extinction in the 1980s.
Zoo populations of these desert antelope are thriving because of cooperation between North American and European zoos. Despite zoo breeding success, individuals of each species are widely dispersed globally which makes genetic management (to prevent inbreeding) difficult. Scientists at the Zoo have pioneered artificial insemination techniques for the scimitar-horned oryx to help ensure reproduction between valuable, but behaviorally incompatible pairs; eliminate the risks of animal transport; and to provide a means to exchange genes among populations. Success of the program has also lead to reintroduction efforts being made in North Africa. Smithsonian Conservation Biology Institute (SCBI) Director Steve Monfort has been leading this attempt in collaboration with Sahara Conservation Fund.
In addition to individuals at the Zoo, SCBI houses a herd of oryx to contribute to this genetic management program. In April 2010, an oryx calf was born at SCBI—the first in 13 years. The individuals currently residing at the Zoo were subsequently born in June 2011, furthering the success of the program.
Another element of research regarding scimitar-horned oryx has been evaluating novel management strategies in cooperation with the Conservation Centers for Species Survival. This project examines the impact of herd management on loss of gene diversity, animal health, reproductive fitness, animal welfare, social behavior and economics (namely, the cost of managing animals in herds rather than very small groups of two or three animals).
The Zoo has two female scimitar-horned oryx named Dakota and Emma Claire. They share an enclosure at the Cheetah Conservation Station with four Dama gazelles and a pair of Rüppell’s griffon vultures,