Animal Diversity Web

Ge­o­graphic Range

Drom­e­dary camels oc­cupy arid re­gions of the Mid­dle East through north­ern India and arid re­gions in Africa, most no­tably, the Sa­hara Desert. They have also been in­tro­duced to arid re­gions of cen­tral Aus­tralia where some of the only feral pop­u­la­tions now per­sist (Nowak 1991). The orig­i­nal range of their wild an­ces­tors was prob­a­bly south Asia and the Ara­bian penin­sula.

• Biogeographic Regions
• palearctic
  • native
• ethiopian
  • introduced
• australian
  • introduced

Habi­tat

Drom­e­dary camels pre­fer desert con­di­tions char­ac­ter­ized by a long dry sea­son and a short rainy sea­son. In­tro­duc­tion of drom­e­dary camels into other cli­mates has proven un­suc­cess­ful as they are sen­si­tive to cold and hu­mid­ity (Nowak 1991).

• Habitat Regions
• temperate
• terrestrial

• Terrestrial Biomes
• desert or dune
• savanna or grassland

Phys­i­cal De­scrip­tion

Drom­e­dary camels are char­ac­ter­ized by a long-curved neck, deep-nar­row chest, and a sin­gle hump. The hump is com­posed of fat bound to­gether by fi­brous tis­sue, act­ing as food stor­age in times of need. The size of the hump varies with the nu­tri­tional sta­tus of the camel, be­com­ing smaller and lean­ing to one side dur­ing times of star­va­tion. The lips of drom­e­dary camels are thick­ened to allow con­sump­tion of coarse, thorny plants. Drom­e­daries are typ­i­cally caramel brown or sandy brown in color, how­ever, col­oration can range from al­most black to nearly white. Hair length is longer on the throat, shoul­der, and hump areas. The feet of drom­e­daries are pad-shaped and adapted for trav­el­ing on sand. They can be eas­ily in­jured on sharp stones and are un­suit­able for slip­pery or muddy con­di­tions. Male drom­e­daries, in com­par­i­son to fe­males, are about 10% heav­ier, weigh­ing 400-600 kg, and are about 10 cm taller at shoul­der height, mea­sur­ing 1.8-2.0 m. Ad­di­tion­ally, male drom­e­daries have an in­flat­able soft palate which is used to at­tract fe­males. Drom­e­dary camels have a total of 34 teeth, with a den­tal for­mula of 1/3; 1/1; 3/2; 3/3. (Kohler-Rollef­son 1991)

Drom­e­dary camels have re­mark­able adap­ta­tions for their desert lifestyle. Their eyes are pro­tected from blow­ing sand and dust by a dou­ble row of eye­lashes. Ad­di­tion­ally, at the onset of a sand­storm, these camels have the abil­ity to close their nos­trils to pre­vent sand from en­ter­ing (Phoenix Zoo 1995). Drom­e­dary camels are able to con­serve water in a va­ri­ety of ways. Water is con­served by the camel's abil­ity to fluc­tu­ate its body tem­per­a­ture through­out the day from 34 de­grees Cel­sius to 41.7 de­grees Cel­sius. This fluc­tu­a­tion in body tem­per­a­ture al­lows the camel to con­serve water by not sweat­ing as the ex­ter­nal tem­per­a­ture rises. Groups of camels also avoid ex­cess heat from the en­vi­ron­ment by press­ing against each other. Drom­e­dary camels can tol­er­ate greater that 30% water loss, a con­di­tion which is lethal for most other mam­mals at 15%. Water is ex­pended pri­mar­ily from in­ter­sti­tial and in­tra­cel­lu­lar bod­ily flu­ids. Fur­ther­more, drom­e­dary camels can re­hy­drate quickly, being ca­pa­ble of drink­ing 100 L of water in just 10 min­utes, a feat which would be lethal to any other mam­mals. (Schmidt-Nielsen 1979, Schmidt-Nielsen et al 1956)

• Other Physical Features
• endothermic
• heterothermic
• bilateral symmetry

• Sexual Dimorphism
• male larger
• sexes shaped differently

• Range mass

  300 to 690 kg

  660.79 to 1519.82 lb

• Average basal metabolic rate

  224.779 W

  AnAge

Re­pro­duc­tion

Dur­ing com­pe­ti­tion for fe­males, males threaten each other by mak­ing low noises with the fleshy fold of their mouths, stand as tall as pos­si­ble, and re­peat a se­ries of head move­ments in­clud­ing low­er­ing, lift­ing, and bend­ing their necks back­wards. Upon con­fronta­tion, fight­ing males at­tempt to bring their op­po­nent to the ground by bit­ing at his legs and tak­ing the op­po­nent's head in be­tween his jaws. Cop­u­la­tion time ranges from 7-35 min­utes, av­er­ag­ing 11-15 min­utes.

• Mating System
• polygynous

Fe­males reach sex­ual ma­tu­rity around age 3 and mate around age 4 or 5. Males begin to rut by age 3, but do not reach full sex­ual ma­tu­rity until age 6. Typ­i­cally, males and fe­males are sea­sonal breed­ers. Breed­ing oc­curs in win­ter and over­laps with the rainy sea­son; both vary in re­spect to the camel's ge­o­graphic range. The onset of the breed­ing sea­son is be­lieved to be cued by nu­tri­tional sta­tus of the camel and the daylength. The ges­ta­tion pe­riod typ­i­cally lasts for a pe­riod of 15 months, fol­lowed by the birth of a sin­gle calf.

• Key Reproductive Features
• iteroparous
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• fertilization
  • internal
• viviparous

• Breeding interval

  Female camels give birth to young once every two years.

• Breeding season

  Breeding occurs during the winter, or rainy season.

• Range number of offspring

  1 to 2

• Average number of offspring

  1

• Average number of offspring

  1

  AnAge

• Range gestation period

  370 to 440 days

• Range time to independence

  12 to 24 months

• Average age at sexual or reproductive maturity (female)

  3 years

• Average age at sexual or reproductive maturity (female)
  Sex: female

  1095 days

  AnAge

• Average age at sexual or reproductive maturity (male)

  6 years

• Average age at sexual or reproductive maturity (male)
  Sex: male

  2191 days

  AnAge

Calves can move freely by the end of their first day. Ma­ter­nal care, in­clud­ing lac­ta­tion, gen­er­ally lasts for 1 to 2 years. Calves typ­i­cally ex­pe­ri­ence a growth rate of .19-.31 kg/day for the first year. (Gau­thier-Pilthers and Dagg 1981, Kohler-Rollef­son 1991)

• Parental Investment
• precocial
• female parental care

Lifes­pan/Longevity

Drom­e­dary camels have a lifes­pan of about 40-50 years (Busch Gar­dens 1996).

• Range lifespan
  Status: captivity

  50 (high) years

• Typical lifespan
  Status: captivity

  40 to 50 years

• Average lifespan
  Status: wild

  40.0 years

  Max Planck Institute for Demographic Research

Be­hav­ior

With the ex­cep­tion of rut­ting males, drom­e­dary camels dis­play lit­tle ag­gres­sive be­hav­ior. Con­fronta­tions among drom­e­dary camels in­clude push­ing each other with their whole body or low­ered head and neck; snap­ping at each other with­out bit­ing; and oc­ca­sion­ally vom­it­ing cud when they are hurt or ex­cited. Drom­e­dary camels usu­ally form groups of 2 to 20 in­di­vid­u­als. The basic so­cial unit is the fam­ily, con­sist­ing of one male, and one to sev­eral fe­males, subadults, and young. The male within the fam­ily unit pre­vents con­tact be­tween fe­male camels within the fam­ily and stray males by ei­ther stand­ing or walk­ing in be­tween them, or by dri­ving the stray males away. The male is the dom­i­nant mem­ber of the fam­ily group and di­rects the fam­ily from the rear while the fe­males take turns lead­ing. Drom­e­daries tend to travel by walk­ing sin­gle file. Drom­e­dary camels find com­fort in scratch­ing parts of their body with their front or hind legs, or with their lower in­cisors. They are also often ob­served rub­bing against trees. Ad­di­tion­ally, they seem to like to roll in sand (Gau­thier-Pilthers and Dagg 1981, Kohler-Rollef­son 1991).

• Key Behaviors
• terricolous
• diurnal
• motile
• nomadic
• social

Com­mu­ni­ca­tion and Per­cep­tion

• Perception Channels
• tactile
• chemical

Food Habits

Drom­e­dary camels are her­biv­o­rous. They eat pri­mar­ily thorny plants, dry grasses and salt­bush; how­ever, they will eat most any­thing that grows in the desert (Oak­land Zoo 1993). Drom­e­daries pri­mar­ily browse, with shrubs and forbs com­pos­ing up to 70% of their diet. About 8-12 hours/day is spent graz­ing with equal amounts spent ru­mi­nat­ing (Kohler-Rollef­son 1991). When for­ag­ing, camels tend to spread over large areas and se­lect only a few leaves from each plant. This type of feed­ing be­hav­ior re­duces the stress on the plant com­mu­ni­ties and eases com­pe­ti­tion with other arid re­gion her­bi­vores (Busch Gar­dens 1996). For the camels, this kind of for­ag­ing may re­duce their in­take of any par­tic­u­lar plant toxin by for­ag­ing on the widest va­ri­ety of fo­liage. Ad­di­tion­ally, drom­e­daries need 6 to 8 times as much salt as other an­i­mals for ab­sorp­tion and stor­age of water. Con­se­quently, 1/3 of their food in­take must be halo­phytic plants. Drom­e­daries browse up to a height of 3.5 m, break­ing off branches or strip­ping off the leaves in one move­ment. While brows­ing, they use their lips to grasp the food, then chew each bite 40-50 times. The mouth is kept open while chew­ing thorny food (Kohler-Rollef­son 1991).

• Primary Diet
• herbivore
  • folivore

• Plant Foods
• leaves

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Drom­e­dary camels are used as beasts of bur­den by hu­mans and also pro­vide hu­mans with milk, meat, wool, leather, and fuel from dried ma­nure. Through these ser­vices, drom­e­dary camels have en­abled hu­mans to in­habit ex­tremely arid re­gions. Drom­e­dary hus­bandry is in­creas­ing today, and is being rec­og­nized as an eco­log­i­cally-sound method of pro­duc­ing pro­tein rich food in arid areas (Phoenix Zoo 1995).

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

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

Drom­e­dary camels may, by virtue of their size, hurt hu­mans, but with ap­pro­pri­ate hus­bandry this is un­likely to occur.

Con­ser­va­tion Sta­tus

Since drom­e­dary camels are do­mes­ti­cated they have no spe­cial con­ser­va­tion sta­tus (Busch Gar­dens 1996).

• IUCN Red List

  No special status

• US Federal List

  No special status

• CITES

  No special status

Other Com­ments

Drom­e­dary camels are no longer con­sid­ered wild an­i­mals. Drom­e­dary camels are semi-do­mes­ti­cated an­i­mals, freely rang­ing, but under herds­man con­trol. In fact, drom­e­dary camels have been "ex­tinct" from the wild for the past 2000 years. The ear­li­est ev­i­dence for drom­e­dary do­mes­ti­ca­tion dates to about 4,000 years ago on a small is­land off the Abu Dhabi coast. North­ern Ara­bian tribes began to use drom­e­dary camels as rid­ing an­i­mals around 3,100 years ago (Kohler-Rollef­son 1991). The only sur­viv­ing feral herds of drom­e­dary camels are those found in Aus­tralia. In­tro­duced, feral drom­e­dary camels were also found in the south­west­ern United States until about 1905.

Con­trib­u­tors

Robert Nau­mann (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor.

Ref­er­ences

Busch Gar­dens. 1996. An­i­mal Bytes: Drom­e­dary Camel. http://​crusher.​bev.​net/​education/​seaworld/​animal_​bytes/​dromedary_​camelab.​html.​

Gau­thier-Pilthers H. and A. Dagg. 1981. The camel, its evo­lu­tion, ecol­ogy, be­hav­ior and re­la­tion­ship to man. Chicago: Uni­ver­sity of Chicago Press.

Kohler-Rollef­son. 1991. Camelus drom­e­dar­ius. In: Mam­malian Species. No. 375.

Nowak, R.M. (ed). 1991. Walker's Mam­mals of the World. Vol II. Bal­ti­more: John Hop­kins Uni­ver­sity Press.

Oak­land Zoo. 1997. Drom­e­dary Camel. http://​www.​oaklandzoo.​org/​oz/​zoo/​atoz/​azcamel.​html.​

Phe­noix Zoo. 1995. Drom­e­dary Camel (Ara­bian Camel) http://​aztec.​inre.​asu.​edu/​phxzoo/​camel_​dr.​html.​

Schmidt-Nielsen, K. 1979. Desert An­i­mals, Phys­i­o­log­i­cal Prob­lems of Heat and Water. New York: Dover Pub­li­ca­tions Inc.

Schmidt-Nielsen, B. K. Schmidt-Nielsen, T.R. Houpt and S.A. Jar­num. 1956. Water bal­ance of the camel. Amer­i­can Jour­nal of phys­i­ol­ogy. 185: 185-194.