Camels (extant/living species; Camelus spp.): Physical Characteristics

Body measurements

Data source: Franklin (2011)

General

• Unlike their llama/vicuna/guanaco relatives, all camel species have:
  • At least one hump on their backs
  • Long curved necks
  • Broad, large feet
  • Tufted tails
  • Four teats rather than two
  • Annual molt 
• Domestic camels have been selectively bred over many years
  • Hybridization between species has occurred in ancestry of both domestic species

Feet

• Large, broad ‘elastic’ pad – hooves are 2 fingernail-like toenails on front of pad.
  • Unique among mammals
  • Other ungulates walk on tips of hoof-covered toes.
• Wild Bactrian’s hoof is claw-like.

Humps

• Composed of fibrous tissue and fat.
  • When fat is metabolized, it acts as a source of energy.
  • Concentration of body fat in humps is advantage in hot climate
    • Minimizes its presence throughout the rest of body
    • This reduces heat-trapping that occurs with insulating layers of fat.
• Available nutrition determines size and shape - humps nearly disappear with starvation.
• Not used for water storage.

Nostrils

• Slit-like - can be closed to protect against blowing sand.
• Special nasal cavities moisten air on way in, trap moisture going out.

Eyes/Eyelids

• Long lashes protect against blowing sand.
• Bony arch over eye acts as sun shield.

Ears

• Small and rounded
• Hairs protect ears from blowing sand.

Mouth

• Prehensile lips, upper split in 2 halves.
• Incisors and canine teeth grow though out life.
  

Wild Bactrian camel

• 2 humps: small, pointed, conical
• Frame: small and lithe relative to domestic Bactrian; laterally compressed (Mongolian name ‘havtagai’ means ‘flat’)
• Legs: slender, no callosities on knees
• Feet: narrow
• Hair: tan or grayish on body; long and dark brown on upper legs, neck, top of humps, tail

Domestic Bactrian camel

• 2 humps: large, irregularly shaped, may become flaccid and flop to one side in adult
• Shorter than dromedaries
• Legs: short and stout
• Feet: broad, 2-toed, cushioned by fat
• Hair: long and dark; annual molt

Dromedary camel

• 1 hump: more elastic than Bactrian, shrinks with age instead of flopping to side
• Frame: lighter than Bactrian
• Legs: longer and more slender than Bactrian
• Hair: short, light-colored
  

Adaptations for extremely dry environment

• Red blood cells are oval (round in other mammals) Can flow quicker in a dehydrated state.
• Urine is more concentrated than other animals (less water loss).
• Dung is dry.
• The kidneys and intestines are good at retaining water.
• Can tolerate loss of water equal to over 30% of body weight (Franklin, 2011)
  • Most mammals die if they lose 15%
• Wild Bactrian camel (not domestic) is able to drink saltwater slush when fresh water is unavailable.

Adaptations for tolerating extreme heat

• Able to endure temperature extremes, from -40°F in January to over 100°F in summer.
• Have only 25% the number of sweat glands as found in cattle
• Only sweat when body temperatures reach 41-42°C (105.8-107.6°F)
• Long legs keep bodies further from the hot ground to reduce overheating.

Adaptations for blowing sand

• Long eyelashes and ear hairs form a barrier against blowing sand.
• Slit-like nostrils can close.

Because fat is concentrated in the hump, and not spread over the rest of the body), it helps a camel stay cooler.

When the fat in a camel's hump is metabolized, it becomes a sourch of energy.

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.

Franklin (2011)
Klingel (1990)
Kohler-Rollefson (1991)
Wild Camel Protection Foundation