Arabian oryx

Appearance

An Arabian oryx stands about 1 m high at the shoulder and weighs around 70 kg. 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 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. 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.

Naming

The taxonomic name "Oryx leucoryx" is from the Greek "orux" and "leukos". 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". 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". In 1826, Martin Lichtenstein confused matters by transferring the name "Oryx leucoryx" to the scimitar-horned oryx which was found in the Sudan by the German naturalists Wilhelm Friedrich Hemprich and Christian Gottfried Ehrenberg. 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. Though this name was to persist for many years, Oldfield Thomas renamed the scimitar-horned oryx as "Oryx algazal" in 1903, 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.

Distribution

Historically, the Arabian oryx probably ranged throughout most of the Middle East. In the early 1800s, they could still be found in the Sinai, Palestine, 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.

Status

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 1,000 individuals in the wild, and 6,000–7,000 individuals in captivity worldwide.

Behavior

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, 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.

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, Palestine, 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.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.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, 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.

Food

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.