to be found in the hard sand areas of the flats between the softer dunes and ridges. Arabian oryxes have been reintroduced to Oman, Saudi Arabia, Israel, the United Arab Emirates, Syria, and Jordan. A small population was introduced on Hawar Island, Bahrain, and large semi-managed 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. However, the majority of the population is concentrated in Saudi Arabia. Ecology Feeding The diets of the Arabian oryx consist mainly of grasses, but they eat a large variety of vegetation, including buds, herbs, fruit, tubers and roots. Herds of Arabian oryxes follow infrequent rains to eat the new plants that grow afterwards. They can go for 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. Behavior When the Arabian oryx is not wandering its habitat or eating, it digs shallow depressions in the soft ground under shrubs or trees for resting. They can detect rainfall from a distance and follow in the direction of fresh plant growth. The number of individuals in a 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 oryxes tend to maintain visual contact with other herd members, with 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 Arabian oryxes 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. Adaptations for desert environments The Arabian oryx changes its physiology and behaviour at different times of the year to increase survival during times