The Arabian oryx (Oryx leucoryx) or white oryx is a medium-sized antelope with a distinct shoulder bump, long, straight horns, and a tufted tail. It is a bovid, and the smallest member of Oryx genus, native to desert and steppe areas of the Arabian Peninsula. The Arabian oryx was extinct in the wild by the early 1970s, but was saved in zoos and private preserves and reintroduced into the wild starting in 1980.
In 1986, the Arabian oryx was classified as endangered on the IUCN Red List, and in 2011 it was the first animal to revert to Vulnerable status after previously being listed as extinct in the wild. It is listed in CITES Appendix I. In 2011, populations were estimated at over 1000 individuals in the wild, and 6000–7000 individuals in captivity worldwide.
The taxonomic name Oryx leucoryx is from the Greek orux (gazelle or antelope) and leukos (white). The Arabian oryx is also called the white oryx in English, and is known as maha, wudhaihi, baqar al wash, and boosolah in Arabic.
Russian zoologist Peter Simon Pallas introduced "oryx" into scientific literature in 1767, applying the name to the African eland as Antilope oryx (Pallas, 1767). In 1777, he transferred the name to the Cape gemsbok. At the same time, he also described what we now call the Arabian oryx as Oryx leucoryx, giving its range as "Arabia, and perhaps Libya." In 1816, Henri Marie Ducrotay de Blainville subdivided the antelope group, adopted Oryx as a genus name, and changed the Antilope oryx of Pallas to Oryx gazella (de Blainville, 1818). In 1826, Martin Lichtenstein confused matters by transferring the name Oryx leucoryx to the scimitar-horned oryx (now Oryx dammah) which was found in the Sudan by the German naturalists Wilhelm Friedrich Hemprich and Christian Gottfried Ehrenberg (Lichtenstein, 1826). The Arabian oryx was then nameless until the first living specimens in Europe were donated to the Zoological Society of London in 1857. Not realizing this might be the Oryx leucoryx of previous authors, Dr. John Edward Gray proposed calling it Oryx beatrix after HRH the Princess Beatrice of the United Kingdom (Gray, 1857). Though this name was to persist for many years, Oldfield Thomas renamed the scimitar-horned oryx as Oryx algazal in 1903 (it has since been renamed Oryx dammah), and gave the Arabian oryx back its original name. The confusion between the two species has been exacerbated because both have been called white oryx in English.
Anatomy and morphology 
An Arabian oryx stands about 1 m (39 in) high at the shoulder and weighs around 70 kg (150 lb). Its coat is an almost luminous white, the undersides and legs are brown, and black stripes occur where the head meet the neck, on the forehead, on the nose and going from the horn down across the eye to the mouth. Both sexes have long, straight or slightly curved, ringed horns which are 50 to 75 cm (20 to 30 in) long.
Arabian oryx rest during the heat of the day and can detect rainfall and will move towards it, meaning they have huge ranges; a herd in Oman can range over 3,000 km2 (1,200 sq mi). Herds are of mixed sex and usually contain between two and 15 animals, though herds of up to 100 have been reported. Arabian oryx are generally not aggressive toward one another, which allows herds to exist peacefully for some time.
Other than humans, wolves are the Arabian oryx's only predator. In captivity and good conditions in the wild, oryx have a life span of up to 20 years. In periods of drought, though, their life expectancy may be significantly reduced by malnutrition and dehydration. Other causes of death include fights between males, snakebites, disease, and drowning during floods.
Distribution and habitat 
Historically, the Arabian oryx probably ranged throughout most of the Middle East. In the early 1800s, they could still be found in the Sinai, Israel, the Transjordan, much of Iraq, and most of the Arabian Peninsula. During the 19th and early 20th centuries, their range was pushed back towards Saudi Arabia, and by 1914, only a few survived outside that country. A few were reported in Jordan into the 1930s, but by the mid-1930s, the only remaining populations were in the Nafud Desert in northwestern Saudi Arabia and the Rub' al Khali in the south.
In the 1930s, Arabian princes and oil company clerks started hunting Arabian oryx with automobiles and rifles. Hunts grew in size, and some were reported to employ as many as 300 vehicles. By the middle of the 20th century, the northern population was effectively extinct. The last Arabian oryx in the wild prior to reintroduction were reported in 1972.
Arabian oryx prefer to range in gravel desert or hard sand, where their speed and endurance will protect them from most predators, as well as most hunters on foot. In the sand deserts in Saudi Arabia, they used to be found in the hard sand areas of the flats between the softer dunes and ridges.
Arabian oryx have been reintroduced to Oman, Saudi Arabia, Israel, United Arab Emirates, and Jordan. A small population was introduced on Hawar Island, Bahrain and large semimanaged populations at several sites in Qatar and the UAE. The total reintroduced population is now estimated to be around 1,000. This puts the Arabian oryx well over the threshold of 250 mature individuals needed to qualify for Endangered.
Feeding ecology 
The diets of the Arabian oryx consist mainly of grasses, but they will eat a large variety of vegetation, include trees, buds, herbs, fruit, tubers and roots. Herds of Arabian oryx follow infrequent rains to eat the new plants that grow afterward. They can go several weeks without water. Research in Oman has found grasses of the genus Stipagrostis are primarily taken; flowers from Stipagrostis plants appeared highest in crude protein and water, while leaves seemed a better food source with other vegetation.
Behavioral ecology 
When the oryx is not wandering its habitat or eating, it digs shallow depressions in soft ground under shrubs or trees for resting. They are able to detect rainfall from a distance and follow in the direction of fresh plant growth. The number of individuals in herd can vary greatly (up to 100 have been reported occasionally), but the average is 10 or fewer individuals. Bachelor herds do not occur, and single territorial males are rare. Herds establish a straightforward hierarchy that involves all females and males above the age of about seven months. Arabian oryx tend to maintain visual contact with other herd members, subordinate males taking positions between the main body of the herd and the outlying females. If separated, males will search areas where the herd last visited, settling into a solitary existence until the herd's return. Where water and grazing conditions permit, male oryx establish territories. Bachelor males are solitary. A dominance hierarchy is created within the herd by posturing displays which avoid the danger of serious injury their long, sharp horns could potentially inflict. Males and females use their horns to defend the sparse territorial resources against interlopers.
Importance to humans 
The Hebrew word re’em may refer to the Arabian oryx, although this word could also refer to the extinct aurochs, or some other type of horned mammal. In the King James Version of the Bible, the word re’em is translated as unicorn.
Unicorn myth 
An alternative origin of the mythical one-horned unicorn may have been from sightings of an injured oryx; Aristotle and Pliny the Elder held that the oryx was the unicorn's "prototype". From certain angles, the oryx may be mistaken as having one horn instead of two, and given that its horns are made from hollow bone which cannot be regrown, if an oryx were to lose one of its horns, for the rest of its life it would have only one horn.
The Phoenix Zoo and the Fauna and Flora Preservation Society of London (now Fauna and Flora International), with financial help from the World Wildlife Fund, are credited with saving the Arabian oryx from extinction. In 1962, these groups started the first captive-breeding herd in any zoo, at the Phoenix Zoo, sometimes referred to as "Operation Oryx". Starting with 9 animals, the Phoenix Zoo has had over 200 successful births. From Phoenix, oryx were sent to other zoos and parks to start new herds.
Arabian oryx were hunted to extinction in the wild by 1972. By 1980, the number of Arabian oryx in captivity had increased to the point that reintroduction to the wild was started. The first release, to Oman, was attempted with oryx from the San Diego Wild Animal Park. Although numbers in Oman have declined, there are now wild populations in Saudi Arabia and Israel, as well. One of the largest populations is found in Mahazat as-Sayd Protected Area, a large, fenced reserve in Saudi Arabia, covering more than 2000 km2.
In June 2011, the Arabian oryx was relisted as vulnerable by the IUCN Red List. The IUCN estimated more than 1000 Arabian oryx in the wild, with 6000–7000 held in captivity worldwide in zoos, preserves, and private collections. Some of these are in large, fenced enclosures (free-roaming), including those in Syria (Al Talila), Bahrain, Qatar, and UAE. This is the first time the IUCN has reclassified a species as vulnerable after it had been listed as extinct in the wild. The Arabian oryx is also listed in CITES Appendix I.
On June 28, 2007, Oman's Arabian Oryx Sanctuary was the first site ever to be removed from the UNESCO World Heritage List. UNESCO's reason for this was the Omani government's decision to open 90% of the site to oil prospecting. The Arabian oryx population on the site has been reduced from 450 in 1996 to only 65 in 2007. Now, fewer than four breeding pairs are left on the site.
See also 
- Arabian Oryx Sanctuary—a former World Heritage Site in Oman
- IUCN SSC Antelope Specialist Group (2011). Oryx leucoryx. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 20 June 2011. Database entry includes justification for why this species is listed as Vulnerable.
- Talbot, Lee Merriam (1960). A Look at Threatened Species. The Fauna Preservation Society. pp. 84–91.
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- "Conservation Programme for Arabian Oryx: Taxonomy & description". National Wildlife Research Center. 2007. Retrieved 2009-11-15.
- Paul Massicot (2007-02-13). "Arabian Oryx". Animal Info. Archived from the original on 25 January 2008. Retrieved 2008-01-11.
- "Arabian Oryx". The Phoenix Zoo. Archived from the original on 15 February 2008. Retrieved 2008-01-27.
- "The Oryx Facts". The Arabian Oryx Project. Archived from the original on 12 January 2008. Retrieved 2008-01-27.
- Stanley-Price, Mark (July/August 1982). "The Yalooni Transfer". saudiaramcoworld.com. Saudi Aramco World. Archived from the original on 10 June 2011. Retrieved 31 December 2012.
- Spalton, J. A. (1999). "The food supply of Arabian oryx (Oryx leucoryx) in the desert of Oman". Journal of Zoology 248 (248): 433–441. doi:10.1111/j.1469-7998.1999.tb01043.x.
- Leu, H. (2001) "Oryx leucoryx" (On-line), Animal Diversity Web.
- How to go wild. New Scientist (1989-10-28). Retrieved on 2013-01-01.
- Science & Nature – Wildfacts – Arabian oryx. BBC (2012-04-27). Retrieved on 2013-01-01.
- "Arabian Oryx". Natural History Museum of Los Angeles County. Archived from the original on 2007-10-10. Retrieved 2008-01-25.
- Rice, Michael (1994). The archaeology of the Arabian Gulf, c. 5000–323 BC. Routledge. p. 63. ISBN 0415032687.
- Tongren, Sally (1981). What's for lunch: animal feeding at the zoo. GMG Publications.
- The Arabian Oryx Project – Timeline. oryxoman.com
- Phoenix Zoo Species Survival Plan. Phoenixzoo.org (2006-01-03). Retrieved on 2013-01-01.
- Saltz, D. (1998). "A long-term systematic approach to planning reintroductions: the Persian fallow deer and the Arabian oryx in Israel". Animal Conservation 1 (4): 245. doi:10.1111/j.1469-1795.1998.tb00035.x.
- Gilad, O., Grant, W.E., and Saltz, D. (2008). "Simulated dynamics of Arabian Oryx (Oryx leucoryx) in the Israeli Negev: Effects of migration corridors and post-reintroduction changes in natality on population viability". Ecological Modelling 210: 169. doi:10.1016/j.ecolmodel.2007.07.015.
- Platt, John (17 June 2011). "Arabian Oryx Makes History as First Species to Be Upgraded from "Extinct in the Wild" to "Vulnerable"". scientificamerican.com. Retrieved 20 June 2011.
- "Appendices I, II and III". cites.org. CITES. Retrieved 20 June 2011.
- "Oman's Arabian Oryx Sanctuary: first site ever to be deleted from UNESCO's World Heritage List". UNESCO World Heritage Centre. Archived from the original on 18 January 2008. Retrieved 2008-01-16.