The Old World camels fall basically into two species, the Arabian and the Bactrian. Linnaeus named the two species known as Camelus dromedarius and Camelus bactrianus. The Arabian camels have one hump on their backs and the Bactrian have two humps. They both live in desert areas. There are still Bactrian camels that exist in the Gobi desert as wild animals, but their numbers are dwindling due to human encroachment.
The Arabian camels no longer have wild relatives but exist as domesticated animals. It has been suggested that they are actually derived from the Bactrian camels and lost one of their humps in the process of domestication. Archeologists think that domestication took place in the middle or southern part of the Arabian Peninsula about 3,000 B.C. From there, they moved to other parts of the Middle East and eventually into North Africa. They are used: as pack animals; for human transport; and as a source of wool, hides, meat and milk. Some are used for racing competitions. Today, there are several breeds. The most popular and well known breed is the dromedary. Other riding breeds include the Mehari of the Sahara and the Mahri of Pakistan.
An interesting part of the use of camels had been their introduction into countries far from their origin. Today, they are seldom transported to other countries other than for exhibit. Small land owners prefer the smaller, more easily cared for and more tractable South American camelids. Some of the more notable introductions have occurred in the last 200 years. They took place in Tuscany, Spain, Australia, the Canary Islands and South America. In the U.S., they have been introduced in Virginia and in the desert areas of Arizona and Nevada.
Although there are environmental conditions in other parts of the world that can support these animals, the most successful introductions were in Australia. They were first imported from India by the British in 1860 and 1866. The camels became very important in the development of the interior of the country. Camel trains carried supplies to the outback mining and ranching stations, and aided in the general exploration and construction of transcontinental telegraph lines and railroads. After the use of autos and trucks began to make the camel obsolete, they were turned loose and established feral herds. Although they do not eat the same foods as cattle and sheep, some ranchers consider them vermin.
Certainly some of the more interesting characteristics of camels are the physiological changes that have taken place to allow them to live in such dry environments. They exhibit several notable adaptations: long eye lashes that protect their eyes from sand, control of the opening of the nostrils, a body structure that allows the animals to stand above the hot sand and allow for heat loss, and the ability to reach tall forage. The body temperature of the animal can fluctuate between 93 and 105 F; therefore, sweating is reduced. Their ability to withstand water deprivation is truly remarkable and stems from several factors. They don’t over heat, can withstand water loss, and store fats in the hump for use in times of food and water deprivation. In times of dehydration, the water seems to be lost from tissues, but not blood. For this reason there is no circulatory distress and the animals can sustain a loss of up to 25% of their body weight. (Humans lose water from blood and tissue and will die of sluggish circulation at a loss of 12% of their body water.) Camels can also re-hydrate very quickly. They are considered quite bad-tempered animals that are unintelligent, untrustworthy and can render a nasty bite. Their adult teeth are similar to the fangs of a canine.
Arabian Camels
They are big animals. They can stand 6 feet at the shoulder and weigh about 1100 pounds. As pack animals, they can carry up to approximately 400 pounds. They have not changed much from their wild ancestors. They are a little larger and have larger humps. There is some color variation in the domestic breeds, and they are not very distinct. There are two general types of dromedaries among the many breeds. They have been selectively bred as strong pack and draught animals, or as long legged riding and racing camels such as the Mehari of North Africa. The geographic range for Arabians is Northern Africa and the Middle East. The Arabian overlaps with the Bactrian camel in the areas of Afghanistan, Pakistan, and Southwest Asia.
Bactrian Camels
The Bactrian camels of Central Asia, China, and Mongolia are important to the indigenous people. They follow their herds of horses and other grazing animals. They are much heavier, used as pack and draught animals, and can withstand the very low temperatures of the winter and the high temperatures of the summer. They are also stocky, and much more hairy and wooly than the Arabian species. They are used as a source of milk and meat. Their dried dung is used as fuel.