Camels belong to the family Camelidae. There are two 'true' camel species and four South American camelids belonging to the Camelidae family. Dromedaries and Bactrians are the true camels while the vicuna, alpaca, llama and guanaco make up the four South American members of Camelidae.
Differences Between Dromedaries and Bactrian Camels
The most easily discernable difference between dromedaries and Bactrian camels is that dromedaries have one hump and Bactrians have two. Furthermore there are two types of Bactrian camel – the wild and the domesticated. The binomial name for the domesticated Bactrian is camelus bactrianus while the wild Bactrian goes by the name of camelus bactrianus ferus.
The wild Bactrian is regarded as a completely different species. It has three more genes than domestic camels and can cope with much saltier water. It is more athletic-looking. The shape is more slender. The feet and humps are smaller and it has shorter hair. In its native habitat, the Bactrian has to cope with extremes of temperature which he does with equanimity. While they can be of any colour, they are generally somewhere between beige and dark brown. For winter, they grow a shaggy coat which is then shed in great lumps when warmer weather marks the arrival of spring. As a general rule, wild camels stay in groups which include females and their offspring and an adult male. Adolescents are sometimes seen in the groups.
The domesticated Bactrian is common in central Asia and is regarded as a very valuable commodity. The lifespan stretches from 25 to 45 years. They are used for riding and as pack and draught animals. The females are milked. Butter, curd and cheese are produced from the milk and are used to treat anaemia, tuberculosis, jaundice and diabetes. As with dairy cows, the flavour of the milk reflects the vegetation consumed. Camels supply meat for their owners and the bones and 'wool' is used for various items.
The Bactrian is short-legged and measures 183cm to 229cm feet at the shoulder. They weigh between 590 to 952kg. The height to the top of the hump may be 274cm. Bactrians have two humps which are not used to store water but which consist of fatty tissue. When food is limited, the camel will reabsorb the fat stored in its hump(s). Up to 200kg can be lost by a camel in a season if there is not enough to eat. If a Bactrian has been without water for a few days, it will drink 30 gallons in ten minutes. But, during cold weather and if eating green feed, it will get its moisture needs from the vegetation it consumes. Camels need eight times the amount of salt that sheep need.Credit: http://commons.wikimedia.org/wiki/File:Bk_Bactrian_Camel-2,_Kristiansand_Zoo,_Norway.jpg
In the above image, the first hump is very underdeveloped. The animal has also shed part but not all of its coat. By contrast, the image below shows a Bactrian with two full humps. It also appears to have lost most of its coat.Credit: http://commons.wikimedia.org/wiki/File:Bactrian.camel.sideon.arp.jpg
Camels are well adapted to life in the desert.
It has bushy eyebrows and a double row of long eyelashes which protect the eyes. The inside of the ears is hairy helping to keep out sand. During sandstorms the nostrils and lips close tightly. Its urine is concentrated. It sweats very little. It changes its body temperature according to the ambient temperature. The soft, flat feet spread and do not sink into the sand.
Both sexes exhibit changes during the breeding season. Males become aggressive and will fight with other males. Domestic males become difficult to handle and untrustworthy. An evil-smelling, brown discharge is produced by glands behind the head. The testicles become enlarged. Both sexes spray urine over the legs and use the tail to flick urine over the legs and back. The vulva of the female swells and becomes moist. She will become restless and will go off on her own. When ready to mate, the cow kneels on all fours and the male mounts her from the rear.
The gestation period for the two humped camel is 406 days, slightly more than for the dromedary. One to two offspring will be born and will be on their feet and nursing in a short time. Within 24 hours they are able to follow their mother. The cow does not bite through the umbilical cord and she doesn't lick and clean the newborn calf. However, she is still very protective of it. Most calves are born in March or early April. Cows first calve at five years of age and calve only every two years. They may produce milk for 9 to 18 months after calving.
Camels are herbivores but differ from true ruminants in a number of ways, mostly in the arrangement of their dentition. There are vestigial central incisors in the upper jaw and the third incisors have developed into canine-like tusks. They also have true canines and tusk-like premolars. The upper lip is split in two with each part independently mobile. Another difference is that the legs are attached to the body only at the top of the thigh. Hence camels have to lie down by resting on their knees and tucking the legs underneath the body. They also have a three-chambered rather than a four-chambered digestive tract.
Camels have a very tough mouth. They relish thorny shrubs and scrubs that other animals cannot eat. The split lip enables them to delicately pick off twigs and leaves between thorns. Because of their longish necks, they can reach perhaps 3 metres into trees and bushes. Camels spend much of the day occupied with food. They may spend eight hours a day eating and a similar amount of time chewing their cud.
External and internal parasites plague camels. Mites and ticks are common and cause skin problems. Worm infestations are also common. Surra or trypanosomiasis is very common and is caused by very small parasites. Once an animal has the disease, it is spread by biting flies.
The wild Bactrian is regarded as critically endangered. The Chinese province of Xinjiang and Gansu is believed to have around 600 camels and the Gobi Desert area of Mongolia is home to another 300. Poaching and competition from other livestock species has seen the number of wild Bactrian camels decline. Conservation efforts have been developed but the wild Bactrian camel is now listed among the top ten species at risk of extinction.