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Bactrian camel

This is the latest accepted revision, reviewed on 21 October 2024.

This article is about the domesticated and feral Bactrian camel. For the critically endangered wild species, see Wild Bactrian camel.

The Bactrian camel (Camelus bactrianus), also known as the Mongolian camel, domestic Bactrian camel or two-humped camel, is a large camel 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]

Bactrian camel
Shanghai Zoo
Domesticated
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Family: Camelidae
Genus: Camelus
Species:
C. bactrianus
Binomial name
Camelus bactrianus
Synonyms[1]
List
  • Camelus bocharius Kolenati (1847)
  • Camelus caucasicus Kolenati (1847)
  • Camelus genuinus Kolenati (1847)
  • Camelus orientalis J. Fischer (1829)
  • Camelus tauricus J. Fischer (1829)

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. Domestic Bactrian camels do not descend from wild Bactrian camels, with the two species having split around 1 million years ago.

Taxonomy

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Phylogenetic relationships of domestic Bactrian camels compared to living and recently extinct camels[4]
Camelidae

Lamini (llamas)

Camelini

†Camelops

Camelus

Camelus dromedarius (dromedary)

†Camelus knoblochi

Camelus ferus (wild Bactrian camel)

Camelus bactrianus (domestic Bactrian camel)

The Bactrian camel shares the genus Camelus with the dromedary (C. dromedarius) and the wild Bactrian camel (C. ferus). The Bactrian camel belongs to the family Camelidae.[1][5] The ancient Greek philosopher Aristotle was the first European to describe the camels: in his 4th century BCE History of Animals, he identified the one-humped Arabian camel and the two-humped Bactrian camel.[6][7] The Bactrian camel was given its current binomial name Camelus bactrianus by Swedish zoologist Carl Linnaeus in his 1758 publication Systema Naturae.[8]

Though sharing a closer common ancestor with it than with the dromedary, the domestic Bactrian camel does not descend from the wild Bactrian camel, with the two species having diverged hundreds of thousands of years ago, with their mitochondrial genomes estimated to have diverged around 1 million years ago. Genetic evidence suggests that both Bactrian camel species are closely related to the extinct giant camel species Camelus knoblochi which became extinct around 20,000 years ago, which is equidistant from both living Bactrian camel species.[4]

The Bactrian camel and the dromedary often interbreed to produce fertile offspring. Where the ranges of the two species overlap, such as in northern Punjab, Iran and Afghanistan, the phenotypic differences between them tend to decrease as a result of extensive crossbreeding between them. The fertility of their hybrid has given rise to speculation that the Bactrian camel and the dromedary should be merged into a single species with two varieties.[9] However, a 1994 analysis of the mitochondrial cytochrome b gene revealed that the species display 10.3% divergence in their sequences.[10]

Description

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The Bactrian camel is the largest mammal in its native range and is the largest living camel while being shorter at the shoulder than the dromedary. Shoulder height is from 160 to 180 cm (5.2 to 5.9 ft) with the overall height ranging from 230 to 250 cm (7.5 to 8.2 ft),[11][12][13] head-and-body length is 225–350 cm (7.38–11.48 ft), and the tail length is 35–55 cm (14–22 in). At the top of the humps, the average height is 213 cm (6.99 ft).

 

Body mass can range from 300 to 1,000 kg (660 to 2,200 lb), with males weighing around 600 kg (1,300 lb), and females around 480 kg (1,060 lb).[14][2][15] Its long, wooly coat varies in colour from dark brown to sandy beige. A mane and beard of long hair occurs on the neck and throat, with hairs measuring up to 25 cm (9.8 in) long.

The shaggy winter coat is shed extremely rapidly, with huge sections peeling off at once, appearing as if sloppily shorn. The two humps on the back are composed of fat (not water as is sometimes thought). The face is typical of a camelid, being long and somewhat triangular, with a split upper lip. The long eyelashes, along with the sealable nostrils, help to keep out dust in the frequent sandstorms which occur in their natural range. The two broad toes on each foot have undivided soles and are able to spread widely as an adaptation to walking on sand. The feet are very tough, as befits an animal of extreme environments.

Natural habitat

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These camels are migratory, and their habitat ranges from rocky mountain massifs to flat steppe, arid desert, (mostly the Gobi Desert), stony plains and sand dunes. Conditions are extremely harsh – vegetation is sparse, water sources are limited and temperatures are extreme. The coat of the Bactrian camel can withstand cold as low as −30 °C (−22 °F) in winter to 50 °C (122 °F) in summer.[16] 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.

Life history

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A young calf in western Mongolia

Bactrian camels are exceptionally adept at withstanding wide variations in temperature, ranging from freezing cold to blistering heat. They have a remarkable ability to go without water for months at a time, but when water is available they may drink up to 57 liters at once. When well fed, the humps are plump and erect, but as resources decline, the humps shrink and lean to the side. When moving faster than a walking speed, they pace, by stepping forwards with both legs on the same side (as opposed to trotting, using alternate diagonals as done by most other quadrupeds). Speeds of up to 65 kilometres per hour (40 mph) have been recorded, but they rarely move this fast. Bactrian camels are also said to be good swimmers. The sense of sight is well developed and the sense of smell is extremely good. The lifespan of Bactrian camels is estimated at up to 50 years, more often 20 to 40 in captivity.

Diet

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Skull

Bactrian camels are diurnal, sleeping in the open at night and foraging for food during the day. They are primarily herbivorous. With tough mouths that can withstand sharp objects such as thorns, they are able to eat plants that are dry, prickly, salty or bitter, and can ingest virtually any kind of vegetation. When other nutrient sources are not available, these camels may feed on carcasses, gnawing on bones, skin, or various different kinds of flesh. In more extreme conditions, they may eat any material they find, which has included rope, sandals, and even tents. Their ability to feed on a wide range of foods allows them to live in areas with sparse vegetation. The first time food is swallowed, it is not fully chewed. The partly masticated food (called cud) goes into the stomach and later is brought back up for further chewing.

Bactrian camels belong to a fairly small group of animals that regularly eat snow to provide their water needs. Animals living above the snowline may have to do this, as snow and ice can be the only forms of water during winter, and by doing so, their range is greatly enlarged. The latent heat of snow and ice is big compared with the heat capacity of water, forcing animals to eat only small amounts at a time.[17]

Reproduction

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Mother and calf

Bactrian camels are induced ovulators – they ovulate after insemination (insertion of semen into the vagina); the seminal plasma, not the spermatozoa, induces ovulation. Ovulation occurs in 87% of females after insemination: 66% ovulate within 36 hours and the rest by 48 hours (the same as natural mating). The least amount of semen required to elicit ovulation is about 1.0 ml.[18]

Males during mating time are often quite violent and may bite, spit, or attempt to sit on other male camels. The age of sexual maturity varies, but is usually reached at 3–5 years. Gestation lasts around 13 months. One or occasionally two calves are produced, and the female can give birth to a new calf every other year. Young Bactrian camels are precocial, being able to stand and run shortly after birth, and are fairly large at an average birth weight of 36 kg (79 lb). They are nursed for about 1.5 years. The young calf stays with its mother for three to five years, until it reaches sexual maturity, and often helps raise subsequent generations for those years. Wild camels sometimes breed with domesticated or feral camels.

Genome

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Cotswold Wildlife Park

The Bactrian Camels Genome Sequencing and Analysis Consortium provides a C. bactrianus ferus genome using next generation sequencing.[19]

Several effective population size studies have been carried out.[20] They show several bottlenecks in both wild and domesticated Bactrians over the past 350,000 years.[20]

Relationship to humans

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Petroglyphs

The Bactrian camel was domesticated circa ~4,500 BCE.[21] The dromedary is believed to have been domesticated between 4000 BCE and 2000 BCE in Arabia. As pack animals, these ungulates are virtually unsurpassed, able to carry 170–250 kg (370–550 lb) at a rate of 47 kilometres (29 mi) per day, or 4 kilometres per hour (2.5 mph) over a period of four days.[22] The species was a mainstay of transportation on the Silk Road.[23] Furthermore, Bactrian camels are frequently ridden, especially in desertified areas. In ancient Sindh, for example, Bactrian camels of two humps were initially used by the rich for riding. The camel was later brought to other areas such as Balochistan and Iran for the same purpose.[22]

 
Tang dynasty model, owned by Agatha Christie

Bactrian camels have been the focus of artwork throughout history. For example, westerners from the Tarim Basin and elsewhere were depicted in numerous ceramic figurines of the Chinese Tang dynasty (618–907).[citation needed]

United States imports

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Bactrian camels were imported to the U.S. several times in the mid- to late 1800s, both by the U.S. military and by merchants and miners, looking for pack animals sturdier and hardier than horses and mules. Although the camels met these needs, the United States Camel Corps was never considered much of a success. Having brought two shipments of fewer than 100 camels to the U.S., plans were made to import another 1,000, but the US Civil War interrupted this. Most surviving camels of these endeavors, both military and private, were merely turned loose to survive in the wild. As a result, small feral herds of Bactrian camels existed during the late 19th century in the southwest deserts of the United States.[24]

Documentaries

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  • The Story of the Weeping Camel is a 2003 Mongolian documentary/story about a family of nomadic shepherds trying to get a white calf accepted by his mother, which rejected him after a difficult birth.

Military use

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The Indian Army uses these camels to patrol in Ladakh. It was concluded that after carrying out trials and doing a comparative study with a single-humped camel brought from Rajasthan that the double-humped camel is better suited for the task at hand. Colonel Manoj Batra, a veterinary officer of the Indian Army, stated that the double-humped camel "are best suited for these conditions. They can carry loads of 170 kilograms (370 lb) at more than 17,000 feet (5,200 m) which is much more than the ponies that are being used as of now. They can survive without water for at least 72 hours."[25]

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Footnotes

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  1. ^ A mnemonic that helps one to remember the correct English word for each is: "Bactrian" begins with "B", and "Dromedary" begins with "D"; "B" on its side has two humps, whilst "D" on its side has only one hump.

See also

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References

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  1. ^ a b Grubb, P. (2005). "Order Artiodactyla". In Wilson, D.E.; Reeder, D.M (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. pp. 645–646. ISBN 978-0-8018-8221-0. OCLC 62265494.
  2. ^ a b "Bactrian camel". EdgeofExistence.org. EDGE. 2010.
  3. ^ "Quick Facts about Camels' Domestication History". arkbiodiv.com. 2021.
  4. ^ a b Yuan, Junxia; Hu, Jiaming; Liu, Wenhui; Chen, Shungang; Zhang, Fengli; Wang, Siren; Zhang, Zhen; Wang, Linying; Xiao, Bo; Li, Fuqiang; Hofreiter, Michael; Lai, Xulong; Westbury, Michael V.; Sheng, Guilian (May 2024). "Camelus knoblochi genome reveals the complex evolutionary history of Old World camels". Current Biology. 34 (11): 2502–2508.e5. doi:10.1016/j.cub.2024.04.050. PMID 38754423.
  5. ^ Groves, C.; Grubb, P. (2011). Ungulate Taxonomy. Johns Hopkins University Press. p. 32. ISBN 978-1-4214-0093-8.
  6. ^ de Buffon, C. (1791). Natural History, General and Particular. Vol. 6. London, UK: Alexander Strahan. p. 121.
  7. ^ Smith, W.; Anthon, C. (1870). A Dictionary of Greek and Roman Antiquities (3rd ed.). New York, NY: Harper and Brothers Publishers. p. 204.
  8. ^ Linnaeus, C. (1758). Systema Naturæ per Regna Tria Naturae. Vol. 1 (10th ed.). Stockholm, Sweden: Laurentius salvius. p. 65.
  9. ^ Mukasa-Mugerwa, E. (1981). The camel (Camelus dromedarius): A bibliographical review (PDF). Addis Ababa, Ethiopia: International Livestock Centre for Africa. pp. 1–147.
  10. ^ Stanley, H.F.; Kadwell, M.; Wheeler, J.C. (1994). "Molecular evolution of the family Camelidae: A mitochondrial DNA study". Proceedings of the Royal Society B: Biological Sciences. 256 (1345): 1–6. Bibcode:1994RSPSB.256....1S. doi:10.1098/rspb.1994.0041. PMID 8008753. S2CID 40857282.
  11. ^ Makhdoomi, Dil M.; Gazi, Mohsin A.; ul Nabi, Showkat; Ahmed, Shakeel (2013). "Morphometric studies on adult double humped camel of Ladakh, India". Emirates Journal of Food and Agriculture. Animal Science. 25 (7): 544–548. doi:10.9755/ejfa.v25i7.15999.
  12. ^ "Camel fact sheet". Nature. PBS. 2020.
  13. ^ "Bactrian camel". Dimensions.com.
  14. ^ Chen, B.X.; Yuen, Z.X.; Pan, G.W. (1 July 1985). "Semen-induced ovulation in the bactrian camel (Camelus bactrianus)". Reproduction. 74 (2): 335–339. doi:10.1530/jrf.0.0740335. ISSN 0022-4251. PMID 3900379. S2CID 2219773.
  15. ^ "Bactrian Camel". UltimateUngulate.com.
  16. ^ "Bactrian Camel". Highland Wildlife Park. Retrieved 15 July 2022.
  17. ^ Wand, C.; Richardson, C. (November 2009). "Replacing water with clean snow for ewes and beef cows" (PDF). OMAFRA.gov.on.ca. Ontario Ministry of Agriculture, Food, and Rural Affairs. 9–065 AGDEX 424/433. Archived from the original (PDF) on 2 April 2015. Retrieved 9 February 2017.
  18. ^ Chen, B.X.; Yuen, Z.X. & Pan, G.W. (1985). "Semen-induced ovulation in the bactrian camel (Camelus bactrianus)" (PDF). J. Reprod. Fertil. 74 (2): 335–339. doi:10.1530/jrf.0.0740335. PMID 3900379.
  19. ^ This review... Wang, Guo-Dong; Xie, Hai-Bing; Peng, Min-Sheng; Irwin, David; Zhang, Ya-Ping (1 February 2014). "Domestication Genomics: Evidence from Animals". Annual Review of Animal Biosciences. 2 (1). Annual Reviews: 65–84. doi:10.1146/annurev-animal-022513-114129. ISSN 2165-8102. PMID 25384135. ...cites this study: Wang, Zhen; Ding, Guohui; Chen, Gangliang; Sun, Yamin; Sun, Zhihong; Zhang, Heping; Wang, Lei; Hasi, S.; Zhang, Yan; Li, Jianmei; Shi, Yixiang; Xu, Ze; He, Chuan; Yu, Siriguleng; Li, Shengdi; Zhang, Wenbin; Batmunkh, Mijiddorj; Ts, Batsukh; Bat-Ireedui, Shirzana; Gao, Hongwei; Baysgalan, B.; Li, Qing; Jia, Zhi-lei; Wang, Zhaoxia; Wang, Juan; Pan, Lei; Chen, Yongcan; Ganerdene, Yaichil; Liu, Tuya; Cao, M.; He, Fei; Zha-ti, A.; Zheng, Guangyong; Qiu, Feng; Sun, Zikui; Zhao, Lele; Zhao, Wenjing; Liu, Baohong; Li, Chao; Chen, Yun-Qin; Tang, Xiaoyan; Guo, C.; Liu, Wei; Ming, Liang; Cui, Aiying; Li, Yi; Gao, Junhui; Li, Jing; Niu, Shen; Sun, Tao; Zhai, Zhengxiao; Zhang, Min; Chen, Chen; Baldan, T.; Bayaer, Tuman; Li, Yixue; Meng, H.; Bactrian Camels Genome Sequencing and Analysis Consortium (2012). "Genome sequences of wild and domestic bactrian camels". Nature Communications. 3 (1). Nature Portfolio: 1202. Bibcode:2012NatCo...3.1202T. doi:10.1038/ncomms2192. ISSN 2041-1723. PMC 3514880. PMID 23149746. S2CID 13218949.
  20. ^ a b Burger, Pamela Anna (2016). "The history of Old World camelids in the light of molecular genetics". Tropical Animal Health and Production. 48 (5). Springer Science+Business Media: 905–913. doi:10.1007/s11250-016-1032-7. ISSN 0049-4747. PMC 4884201. PMID 27048619.
  21. ^ MacHugh, David E.; Larson, Greger; Orlando, Ludovic (8 February 2017). "Taming the Past: Ancient DNA and the Study of Animal Domestication". Annual Review of Animal Biosciences. 5 (1). Annual Reviews: 329–351. doi:10.1146/annurev-animal-022516-022747. ISSN 2165-8102. PMID 27813680.
  22. ^ a b Rahimdad Khan Molai Shedai; Janat ul Sindh 3rd edition 1993; Sindhi Adbi Board Jamshoro, page 20
  23. ^ Andrea, A.J.; Levi, S.C. (2009). "Afro-Eurasian connectivity across the ages" (PDF). World System History. The Silk Road. Vol. I.
  24. ^ Zentner, Joe. "The desert camel experiment". DesertUSA.com and Digital West Media. Retrieved 9 February 2017.
  25. ^ Bhalla, Abhishek (19 September 2020). "Indian Army to use double-humped camels for transportation, patrolling in Ladakh". India Today.
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