Oryx prefer near-desert conditions and can survive without water for long periods. They live in herds of up to 600 animals. Newborn calves are able to run with the herd immediately after birth. Both males and females possess permanent horns. The horns are narrow, and straight except in the scimitar oryx, where they curve backwards like a scimitar. The horns are lethal — the oryx has been known to kill lions with them, and oryxes are thus sometimes called the sabre antelope (not to be confused with the sable antelope). The horns also make the animals a prized game trophy, which has led to the near-extinction of the two northern species.