Camelus bactrianusBactrian camel

Geographic Range

Camelus bactrianus, also known as the Bactrian camel, inhabits parts of central Asia and western China. The geographic range is now limited to isolated regions of the Gobi and Taklamakan Deserts of Mongolia and Xinjiang. The Bactrian camel's geographic range has been steadily decreasing for the last 30 years. (Chen, et al., 2009; Cui, et al., 2007; Makhdoomi, et al., 2013; Mengoli, et al., 2005; Nowak, 1999)

Habitat

  • Average elevation
    1,580 m
    ft

Physical Description

The distinguishing characteristic that sets Bactrian camels apart from dromedary camels (Camelus dromedarius) is that they have two humps on their backs (dromedary camels have just one). Bactrian camels are large animals with an average height of 2.134 m. The length of the head and body is 2.25-3.45 m, the tail is 0.35-0.55 m long, and the shoulder height is 1.80-2.30 m tall. The weight of the adult camel can range from 300-690 kg. Adult male Bactrian camels are often much larger than the adult females; however the exact measurements have not been acknowledged in scholarly research.

Camel coat color is typically dark brown or a dirty gray color. Exclusive to the Bactrian camel is their long hair (255mm long). The coat is thicker and heavier on the head, neck, humps, forelegs, and tail regions. The drastic seasonal temperature changes in the desert require Bactrian camels to shed their heavy coat when the seasons change.

Despite enduring high ambient temperatures, Bactrian camels have minimal sweat glands. Instead, they have the ability to tolerate an internal temperature increase of 6 degrees Celsius before perspiring, which prevents water loss.

Bactrian camels have a double row of long eyelashes that block harsh winds that often blow sand and dust into the camels' eyes. Their ears are also lined with hair and their top lip is divided. The nostrils can close to shield against dust and sand. There is a connecting indent that runs along each nostril to the cleft top lip so that any extra water or moisture can be trapped in the mouth. The camels' even toed feet are tough and the soles are undivided. (Chen, et al., 2009; Makhdoomi, et al., 2013; Nowak, 1999)

  • Sexual Dimorphism
  • male larger
  • Range mass
    300 to 690 kg
    660.79 to 1519.82 lb
  • Range length
    2.25 to 3.45 m
    7.38 to 11.32 ft

Reproduction

Both camel species are polygynous, where the dominant male will mate with any of the females in the herd. The rutting seasons lasts about three months. The dominant male will often protect and defend the females within the group from other wandering bachelor camels. However, no published articles identify how the alpha male is determined within the group. Throughout the mating season males tend to fight, bite, spit, and snort to intimidate and scare away intruding males. (Elias and Cohen, 1986; Mostafa, 2010; Nowak, 1999; Palmer, 1957; Skidmore, 2011; Smith and Xie, 2008)

The Bactrian camel's breeding season takes place in March and April. Camels are induced ovulators, which means they only ovulate when stimulated by mating. If a female does not have the opportunity to mate, her ovarian follicles will degenerate. Their estrous cycle is about 13-40 days, and receptivity usually last between three and four days. Gestation is 360-440 days, resulting in one or two offspring. Camels can birth up to two offspring every two years, but more than one is rare.

Following this biennial cycle, each female produces an estimated 12 offspring in her lifetime. Calves are born weighing about 37 kg and are fully mobile within the first 24 hours. Calves in the wild are typically weaned within the first two years, but this can happen within one year in captivity. The calf reaches full maturity at age five, sometimes six to eight years for males. It is more common for males to reach sexual maturity before the age of five. Calves live close to their mothers for three to five years, and completely separate once sexually mature. (Elias and Cohen, 1986; Mostafa, 2010; Nowak, 1999; Palmer, 1957; Skidmore, 2011; Smith and Xie, 2008)

  • Breeding interval
    Camels reproduce once every two years.
  • Breeding season
    Breeding season takes place between March and April
  • Range number of offspring
    1 to 2
  • Average number of offspring
    1
  • Average number of offspring
    1
    AnAge
  • Range gestation period
    360 to 440 days
  • Range weaning age
    12 to 24 months
  • Range time to independence
    3 to 6 years
  • Average time to independence
    5 years
  • Range age at sexual or reproductive maturity (female)
    3 to 5 years
  • Average age at sexual or reproductive maturity (female)
    5 years
  • Range age at sexual or reproductive maturity (male)
    3 to 8 years
  • Average age at sexual or reproductive maturity (male)
    5 years

The female camel is particularly invested in her parental duties, and remains so until the calf reaches full sexual maturity. Within the first two years the mother weans the calf, but both mother and baby remain very close to each other. In most cases the young camels stay with their mother until age five, when they reach sexual maturity. Calves learn how to interact properly with the other members of the herd as well as food foraging skills and migratory patterns. Female camels are protective of their young, and become violent if threatened. Because of this attachment, mother camels have been documented mourning the loss of a calf for as long as three months. (Nowak, 1999; Palmer, 1957; Skidmore, 2011; Smith and Xie, 2008)

  • Parental Investment
  • precocial
  • female parental care
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • pre-independence
    • provisioning
      • female
    • protecting
      • female
  • extended period of juvenile learning

Lifespan/Longevity

Bactrian camels have been known to live for as long as 50 years in the wild. However, domesticated camels have never been recorded to live for more than 35.4 years. The average life expectancy for wild Bactrian camels is 30 years. There is limited scholarly literature on any internal or external complications that may contribute to some of the apparent lifespan limitations. ("Camelus bactrianus", 2012; Nowak, 1999; Palmer, 1957; Smith and Xie, 2008)

  • Range lifespan
    Status: wild
    50 (high) years
  • Range lifespan
    Status: captivity
    35.4 (high) years
  • Average lifespan
    Status: wild
    30 years
  • Typical lifespan
    Status: captivity
    35.4 (high) years

Behavior

Wild Bactrian camels typically live in herds of 6-20 members, although they can occasionally be solitary or in groups up to 30 individuals. In their native range, a population density of five camels per 100 square km has been estimated. Camels are not territorial animals. occasionally multiple camel herds will cross paths and form an assembly of camels, which can reach 500 individuals. Camel herds spend the majority of their days moving from one place to another grazing. During the snowy winter months Bactrian camels migrate to the Gobi desert steppe, a broad ecotone that borders many rivers. When the snow melts in the spring, Bactrian camels migrate back to the desert.

The herds consist of one alpha adult male leading adult females and their calves. Once young males reach sexual maturity, the alpha male chases them away, forcing the young males to join a group of bachelor males. If a female in the group is approached by a wandering bachelor male, the intruding male will be chased away by the dominant male. When the dominant male and a bachelor male come in contact, they both display an effort to intimidate their opponent. These displays include: urination, defecation, slapping their tail against their backs, and spreading their hind legs. If none of these displays deter the competitor, the males resort to fighting, includes biting and beating the ground with their feet.

Males tend to not eat during the rutting season, and use their energy reserves to sustain them during this period. Scholarly research hasn't determined why males have adopted this counterintuitive behavior. (Elias and Cohen, 1986; Nowak, 1999; Palmer, 1957; Skidmore, 2011; Smith and Xie, 2008)

  • Range territory size
    50 to 150 km^2

Home Range

Bactrian camels are social animals. These animals aren't territorial, and herds often cross paths to form a large assembly. However, the alpha male of each herd will continue to defend and protect the females in the herd from bachelor males. It has been observed that camels have temporary home ranges of 50-150 square km and yearly ranges of several thousand square km. (Elias and Cohen, 1986; Nowak, 1999; Palmer, 1957; Skidmore, 2011; Smith and Xie, 2008; Elias and Cohen, 1986; Nowak, 1999; Palmer, 1957; Skidmore, 2011; Smith and Xie, 2008)

Communication and Perception

Bactrian camels have a well-developed sense of sight, which is one of the primary ways that camels perceive their surroundings. There have been numerous anatomical studies that have shown that members of the genus Camelus have exceptional eyesight that arose from the unique organization of their retinas. Camels also have well-developed olfactory senses that are extraordinarily strong and sensitive. Camel nostrils are extremely sensitive and can detect odors over long distances, up to 3 km away.

Research on similar ungulates indicates that these animals use pheromones to communicate and send signals. It is thought that camels also use the same or similar pheromones. Vocal communication has been reported in camels, such as deep moans, high pitch squeaks, and groans. Zoos report that camels are very vocal, although there is no scholarly research regarding this. ("Camel", 2013; Harman, et al., 2001; Nowak, 1999; Over, et al., 1990)

Food Habits

Bactrian camels are omnivores, but are primarily herbivores that constantly graze on grasses. As ruminants, these camels have four separate stomachs, one of which is a three-chambered ruminating stomach. Ruminants eat their food followed by regurgitation, allowing them to chew it up a second time.

Camels thrive on all desert vegetation, which includes salty, dry, thorny, and bitter plants. Halophytic plants, which are plants that have been growing in water with a high saline concentration, are a necessary part of Bactrian camel's diet. Their dietary needs and preferences make them ideal candidates for desert life.

In times of environmental stress (little/no available vegetation), camels may eat fish, different types of flesh, bones, skin, and even shoes or other items of fabric. In the winter months, camels often push and dig under the snow to find food, a practice observed only in Bactrian camels.

The humps on the back of the camel are commonly thought to store water, but in actuality the humps store fat. The hump is made up of fatty tissues, which are used to store energy for times when nutrients aren't readily available. The energy reserves in the camels hump can be used in place of both water and food. Camels that are well nourished have humps that stand upright and appear plump and firm. Malnourished camels that are deprived of vital nutrients have smaller and sideways leaning humps. A camel with a nourished hump can live up to a couple of weeks without eating or drinking.

Along with the energy reserves that reside in the fatty tissues of the camel's hump, the stomach is enclosed by chambers filled with water. They can also drink saline water, which in turn causes them to urinate concentrated salt. The camels' kidneys efficiently eliminate the unwanted surplus of salt before returning the water back to the bloodstream. Camels can almost be fully sustained from the water in the vegetation that they consume. They can withstand a large amount of water loss, up to 40 percent of their body weight. Camels can consume up to 57 liters of water to fully restore their body fluid levels. When camels come across an abundant water source, they will drink large amounts of water within a matter of minutes, to refill their water storage. This water storage will become useful during times of drought. (Erdunchaolu, et al., 2001; Mengoli, et al., 2005; Nowak, 1999; Wang, 2002; Erdunchaolu, et al., 2001; Mengoli, et al., 2005; Nowak, 1999; Palmer, 1957; Smith and Xie, 2008; Wang, 2002)

  • Animal Foods
  • birds
  • mammals
  • reptiles
  • Plant Foods
  • leaves
  • wood, bark, or stems
  • seeds, grains, and nuts
  • flowers

Predation

Camelus bactrianus has evolved in a particularly harsh environment that is unfit for the majority of predators. However, leopards (Panthera pardus) and wolves (Canis lupus) are sometimes found roaming around the colder regions of Asia. Camels aren't the leopards and wolves' primary target because of the camels' enormous size and difficulty in killing. These predators mainly ignore camels unless they are starving. Humans (Homo sapiens) are the camels' biggest threat, as they are harvested for meat, hides, wool, sinews, and bone. (Nowak, 1999)

Ecosystem Roles

Camelus bactrianus naturally acquires cryptosporidiosis and gastrointestinal helminthic parasites. A wide range of helminth parasites have been found in the gastrointestinal tract of Bactrian camels. A study was conducted in Iran that examined the occurrence of these gastrointestinal helminths. This study included a sample size of 25 fecal samples, which was 25% of the camel population. Helminth eggs were present in 52% of the fecal samples. Bactrian camels in this study were found to be contaminated with Nematodirus (32%), Trichuris (32%), Marshallagia (28%), Moniezia (28%), and Strongyloides (16%). The protozoan Cryptosporidium parvum is another common parasite found in Bactrian camels. This parasite shows distinct signs including chronic loose stools, reduced appetite, weight loss, and lethargy. The presence of these parasites has significant consequences that can often reduce the individual's lifespan. (Fayer, et al., 1991; Tajik, et al., 2011)

Commensal/Parasitic Species

Economic Importance for Humans: Positive

Camelus bactrianus is extremely useful to humans. Camels are commonly used for transportation throughout desert regions. The anatomical formation of their feet aids in their ability to go long distances in harsh desert conditions. Their ability to go extended periods of time without food or water also makes them ideal transportation on long journeys in the desert. Humans have been relying on camels for 3,500 years for transportation and other marketable reasons. Camels provide many useful byproducts including meat, milk, hides, sinews, and bone. The milk is typically fermented to produce kumis,a drink typically enjoyed by the native people of the Central Asian steppes. The fat in the humps can be melted down and used for cooking purposes. Camel hair is often used to make clothes, blankets, tents, and other fabric containing items. camel dung is frequently used to manufacture fuel. Their hides are incorporated into leather products. Given this multitude of uses, its no surprise that camels are frequently bought, sold, and traded within their range. (Ahmad, et al., 2010; Mostafa, 2010; Palmer, 1957; Skidmore, 2011; Wang, et al., 2013)

  • Positive Impacts
  • food
  • body parts are source of valuable material

Economic Importance for Humans: Negative

For the most part camels have very few adverse effects. Occasionally, camels can become hostile. An aggravated out-of-control camel can injure a human being because of their enormous size, but this is very unlikely. A hungry camel can become a nuisance by eating personal possessions and by spitting. (Nowak, 1999; Palmer, 1957; Skidmore, 2011; Smith and Xie, 2008; Wang, et al., 2013)

  • Negative Impacts
  • injures humans

Conservation Status

Wild Bactrian camels are currently a critically endangered species. It has been determined that there are noticeable genetic differences (3%) between the wild and domestic groups. The domesticated version isn't included in the endangered group, as their population appears to be thriving.

Wild Bactrian camels are predicted to decrease in population size by >80% within the next three generations. The subpopulation in Mongolia is estimated to have had a 46% decrease in population size since 1985, although exact population size was not identified in scholarly research.

Because of hunting and other predators such as wolves (Canis lupus) there is an expected loss of 25-30 animals a year for the Mongoloian subpopulation. Based on these trends, the future of wild Bactrian camels is questionable.

The efforts to conserves the wild version is focused on an isolated population in China/Mongolia that doesn't breed with the domestic camels. Because of the genetic differences between the domestic and wild species, the lack of chances to hybridize is a major contributor to their conservation status. (Hare, 2008; Nowak, 1999)

Other Comments

The IUCN classifies the wild species of Bactrian camel as Camelus ferus. Interestingly, the domesticated form of this species is classified as Camelus bactrianus. Grubb (2005) considers ferus a subspecies of bactrianus. (Hare, 2008)

Contributors

Emily Cutshall (author), Radford University, Karen Powers (editor), Radford University, Tanya Dewey (editor), University of Michigan-Ann Arbor.

Glossary

Palearctic

living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

World Map

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

desert or dunes

in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.

diurnal
  1. active during the day, 2. lasting for one day.
dominance hierarchies

ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females

fertilization

union of egg and spermatozoan

folivore

an animal that mainly eats leaves.

food

A substance that provides both nutrients and energy to a living thing.

herbivore

An animal that eats mainly plants or parts of plants.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

migratory

makes seasonal movements between breeding and wintering grounds

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nomadic

generally wanders from place to place, usually within a well-defined range.

omnivore

an animal that mainly eats all kinds of things, including plants and animals

pheromones

chemicals released into air or water that are detected by and responded to by other animals of the same species

polygynous

having more than one female as a mate at one time

scavenger

an animal that mainly eats dead animals

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

young precocial

young are relatively well-developed when born

References

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Raziq, A., M. Younas, M. Kaker. 2008. Camel- a potential dairy animal in difficult environments. Pakistan Journal of Agricultural Sciences, 45/2: 263-267.

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Smith, A., Y. Xie. 2008. A Guide to the Mammals of China. Princeton, New Jersey: Princteton University Press.

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