Wednesday, February 13, 2013

All about Camelus dromedarius

Camelus bactrianus and Camelus dromedarius, via

A camel is an even-toed ungulate within the genus Camelus, bearing distinctive fatty deposits known as "humps" on its back. The two surviving species of camel are the dromedary, or one-humped camel, which is native to the Middle East and the Horn of Africa; and the Bactrian, or two-humped camel, which inhabits Central Asia. Both species have been domesticated; they provide milk, meat, hair for textiles or goods such as felted pouches, and are working animals.
The term "camel" is derived via Latin and Greek from Hebrew or Phoenician gāmāl, possibly from a verb root meaning to bear or carry (related to Arabic jamala).
The average life expectancy of a camel is 40 to 50 years.[8][9] A full-grown adult camel stands 6 ft 1 in. at the shoulder and 7 ft 1 in. at the hump.[10] Camels can run at up to 40 mph in short bursts and sustain speeds of up to 25 mph.
Camels do not directly store water in their humps. The humps are actually reservoirs of fatty tissue: concentrating body fat in their humps minimizes the insulating effect fat would have if distributed over the rest of their bodies, helping camels survive in hot climates.[16][17] When this tissue is metabolized, it yields more than one gram of water for every gram of fat processed. This fat metabolization, while releasing energy, causes water to evaporate from the lungs during respiration (as oxygen is required for the metabolic process): overall, there is a net decrease in water.
The Horn of Africa has the world's largest population of camels.
Physiological adaptations allow them to withstand long periods of time without any external source of water.[17] Unlike other mammals, their red blood cells are oval rather than circular in shape. This facilitates the flow of red blood cells during dehydration[21] and makes them better at withstanding high osmotic variation without rupturing when drinking large amounts of water: a 1,300 lb camel can drink 53 US gal of water in three minutes.[22][23]

Camels are able to withstand changes in body temperature and water consumption that would kill most other animals. Their temperature ranges from 93 °F at dawn and steadily increases to 104 °F by sunset, before they cool off at night again.[17] Camels rarely sweat, even when ambient temperatures reach 120 °F.[8] Any sweat that does occur evaporates at the skin level rather than at the surface of their coat; the heat of vaporization therefore comes from body heat rather than ambient heat. Camels can withstand losing 25% of their body weight to sweating, whereas most other mammals can withstand only about 12–14% dehydration before cardiac failure results from circulatory disturbance.[23]
When the camel exhales, water vapor becomes trapped in their nostrils and is reabsorbed into the body as a means to conserve water.[24] Camels eating green herbage can ingest sufficient moisture in milder conditions to maintain their bodies' hydrated state without the need for drinking.
The camels' thick coats insulate them from the intense heat radiated from desert sand.[26] Its long legs help by keeping them farther from the hot ground, which can heat up to158 °F.[27][28]

Camels' mouths have a thick leathery lining, allowing them to chew thorny desert plants. Long eyelashes and ear hairs, together with nostrils that can close, form a barrier against sand. If sand gets lodged in their eyes, they can dislodge it using their transparent third eyelid. The camels' gait and widened feet help them move without sinking into the sand.[27][29][30]
The kidneys and intestines of a camel are very efficient at reabsorbing water. Camel urine comes out as a thick syrup, and camel feces are so dry the Bedouins use it to fuel fires.[31][32][33][34]

Dromedaries may have first been domesticated by humans in southern Arabia, around 3,000 BC, the Bactrian in central Asia around 2,500 BC.
Camel milk is a staple food of desert nomad tribes and is sometimes considered a meal in and of itself; a nomad can live on only camel milk for almost a month.[15][31][82][83] Camel milk is rich in vitamins, minerals, proteins, and immunoglobulins;[84] compared to cow's milk, it is lower in fat and higher in lactose, potassium, iron, and vitamin C.
A camel carcass can provide a substantial amount of meat.
The brisket, ribs and loin are among the preferred parts, and the hump is considered a delicacy.[92] The hump contains "white and sickly fat", which can be used to make the khli (preserved meat) of mutton, beef, or camel.[93] Camel meat is reported to taste like coarse beef.
Camel meat has been eaten for centuries. It has been recorded by ancient Greek writers as an available dish in ancient Persia at banquets, usually roasted whole.[97] The ancient Roman emperor Heliogabalus enjoyed camel's heel.[31] Camel meat is still eaten in certain regions, including Somalia, Djibouti, Saudi Arabia, Egypt, Libya, Sudan, Kazakhstan, and other arid regions where alternative forms of protein may be limited or where camel meat has had a long cultural history.[14][31][92]
Camel blood is also consumable, as is the case in northern Kenya, where camel blood is drunk with milk and acts as a key source of iron, vitamin D, salts, and minerals.
There are around 14 million camels alive as of 2010, with 90% being dromedaries.[107] Dromedaries alive today are domesticated animals mostly living in the Horn of Africa, the Sahel, Maghreb, Middle East and South Asia.
The Bactrian camel is, as of 2010, reduced to an estimated 1.4 million animals, most of which domesticated.[34][107][111] The only truly wild Bactrian camels, of which there are less than one thousand, are thought to inhabit the Gobi Desert in China and Mongolia.