exacerbated because both have been called the white oryx in English. Anatomy and morphology An Arabian oryx stands about high at the shoulder and weighs around . Its coat is an almost luminous white, the undersides and legs are brown, and black stripes occur where the head meets 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 long. Arabian oryxes rest during the heat of the day. They can detect rainfall and move towards it, meaning they have huge ranges; a herd in Oman can range over . Packs are of mixed sex and usually contain between two and 15 animals, though herds of up to 100 have been reported. Arabian oryxes 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 safe conditions in the wild, Arabian oryxes have a lifespan 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, 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 oryxes 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 before reintroduction was reported in 1972. Arabian oryxes prefer to range in gravel deserts or hard sand, where their speed and endurance will protect them from most predators and hunters on foot. In the sand deserts in Saudi Arabia, they used