Sunday, April 20, 2008

Bactrian camel (Camelus bactrianus)



This camel is probably the ancestor of all domestic two-humped camels. It is superbly adapted to life in the harsh Gobi Desert, one of the most hostile and fragile regions on the planet. The species can withstand drought, food shortages and even radiation from nuclear weapons testing. Less than 1,000 individuals survive today in only four locations. Classified as Critically Endangered, these animals continue to be threatened by hunting, habitat loss, and competition for resources with introduced livestock.

Evolutionary Distinctiveness
Order: Artiodactyla
Family: Camelidae
Camelids (llamas, vicuñas, alpacas, guanacos and camels) evolved in North America during the Eocene Epoch, over 46 million years ago. They differ from all other mammals in the shape of their red blood cells, which are oval instead of circular. There are six living species in three genera (the Old World Camelus, and the New World Lama and Vicugna). The ancestors of the true camels migrated across the Bering Strait land bridge to Asia some 3-4 million years ago. Camelids also crossed to South America after the formation of the Isthmus of Panama around 3 million years ago. Camels disappeared from North America completely around 10,000 years ago. Today, only two species of camel are generally recognised to survive: Camelus bactrianus (Bactrian or two-humped camel) and C. dromedarius (dromedary or one-humped camel).
Description
Size:

Head and body length: 225-345 cm

Shoulder height: 180-230 cm

Tail length: 35-55 cm
Weight: 300-690 kg
The two-humped Bactrian camel is smaller and more slender than its domestic relative, and is superbly adapted to life in the harsh Gobi Desert. It has a double row of long eyelashes and hairs inside the ears to protect against damage from sand, and the camel’s long slit-like nostrils can be closed for further protection during sandstorms. The foot has a tough undivided sole consisting of two large toes, which spread apart widely for efficient travel across the shifting desert sands. The camel’s fur, which is a light brown or beige colour, is thick and shaggy during the harsh winters and is shed rapidly in the spring.
Ecology
Wild camels are diurnal, sleeping at night in open spaces and foraging for food during the day. Shrubs and grass form the bulk of the diet, with the animals being well adapted to feed on thorns, dry vegetation and salty plants, which other herbivores avoid. Excess fat is stored in the humps and used as a reserve when food is scarce. This enables the camels to go for several days at a time without eating or drinking. Upon finding water they will drink vast quantities rapidly to replace what is missing from their bodies - they can take in as much as 57 litres of water to restore the normal amount of body fluid. If no fresh water is available, the species can drink salty or brackish water with no ill effects (camels are the only land mammals adapted for this). Group size is largely dependent on the amount of food available. Usually the camels can be found travelling in small herds of between 6 and 20 related individuals, led by a single adult male, although larger groups will sometimes congregate around water. The distribution is normally widely scattered, with estimates of population density as low as 5/100 sq km. The camels are highly migratory, and will travel vast distances in search of food and water sources. Breeding usually occurs in winter, often overlapping with the rainy season. Females give birth to their first calf at around 5 years of age and the interbirth interval is usually at least 2 years. Wild camels are thought to live up to 40 years of age.
Habitat
The camels are migratory, and their habitat ranges from rocky mountain massifs to flat arid desert, stony planes and sand dunes. Conditions are extremely harsh – vegetation is sparse, water sources are limited and temperatures are extreme, ranging from as low as -40°C in winter to 40°C in summer. The camels’ distribution is linked to the availability of water, with large groups congregating near rivers after rain or at the foot of the mountains, where water can be obtained from springs in the summer months, and in the form of snow during the winter.
Distribution
The species has suffered a drastic reduction in its range. It now occurs only in three separated habitats in northwest China (Lake Lob, Taklimikan desert and the ranges of Arjin Shan) and one in the Trans-Altai Gobi desert of southwest Mongolia. The largest population lives in the Gashun Gobi (Lop Nur) Desert in Xinjiang Province, China, which was for 45 years used as a test site for nuclear weapons.
Population Estimate
There are approximately 600 individuals surviving in China and 350 in Mongolia. In contrast, there are over 2 million domestic Bactrian camels currently living in Central Asia.
Population Trend
Population size is decreasing. The Mongolian population has almost halved in the last twenty years and there is every indication that the situation is just as serious for the Chinese populations.
Status
Classified as Critically Endangered (CR A3de+4ade) on the 2006 IUCN Red List of Threatened Species.
Threats
The species has suffered greatly at the hands of humans. It has lost habitat to mining and industrial development, and has been forced to compete with introduced livestock for food and water. Farmers hunt the camel for this reason, and many individuals are lost every year when the camels migrate out of protected areas and onto land set aside for grazing. Domestic Bactrian camels are amongst the animals introduced to these areas. They graze alongside reserves containing their wild relatives, and there is much concern that interbreeding and subsequent hybridisation will lead to the loss of the genetically distinct wild camel.
Conservation Underway
The species is listed on Appendix I of the Convention on Migratory Species (CMS or the Bonn Convention). The governments of China and Mongolia have agreed to cooperate in order to protect the species and its fragile desert ecosystem. Assisted by the Wild Camel Protection Foundation (WCPF), the two governments have adopted an ecosystem-based management programme which aims to protect the biodiversity of the Great Gobi Desert. Two reserves have been created – the ‘Great Gobi Reserve A’ in Mongolia in 1982, and the Arjin Shan Lop Nur Nature Reserve in China in 2000. These reserves provide a safe habitat for a wide range of endangered desert animals and plants, as well as the wild camels. The WCPF also aims to increase the population of the species through captive breeding. In 2003 it established a sanctuary in Zakhyn-Us, Mongolia, which has some of the last non-hybridised herds of Bactrian camels. Initial breeding attempts have been successful, with several calves having been born since the programme’s inception.

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