The Bactrian camel (Camelus bactrianus), also known as the Mongolian camel or domestic Bactrian camel, is a large even-toed ungulate native to the steppes of Central Asia. It has two humps on its back, in contrast to the single-humped dromedary.[a] Its population of 2 million exists mainly in the domesticated form.[2] Their name comes from the ancient historical region of Bactria.[3] Domesticated Bactrian camels have served as pack animals in inner Asia since ancient times. With its tolerance for cold, drought, and high altitudes, it enabled the travel of caravans on the Silk Road. Bactrian camels, whether domesticated or feral, are a separate species from the wild Bactrian camel, which is the only truly wild (as opposed to feral) species of camelid in the Old World.