Persian onager the Asiatic wild ass is known simply as onager, it now also serves as the Persian wild ass's scientific name, as well ("Equus hemionus onager"). Information on the basic biology of the subspecies and how it differs from others is lacking, which hampers conservation efforts. Onagers used to be numerous from the Middle East to China. However, until the 19th century, their population has been reduced from several thousand to a few thousand. Currently, more than 600 Persian onagers are living in the wild. Persian wild asses are known to inhabit mountain steppes, semidesert, or desert plains. They are usually
Onager (weapon) could be winched back again. The onagers of the Roman Empire were mainly used for besieging forts or settlements. They would often be armed with large stones that could be covered with a combustible substance and set alight. The onager was used from the 4th century AD until the 6th century AD. The late-fourth century author Ammianus Marcellinus describes 'onager' as a neologism for scorpions and relates various incidents in which the engines fire both rocks and arrow-shaped missiles. The late-fourth or early-fifth century military writer Vegetius stipulates that a legion ought to field ten onagers, one for each cohort.