Have behavioural adaptations that minimizes exposure to heat, eg. always faces the sun, therefore exposing as small a surface as possible to the sun and thus taking up less heat.
– ability to endure extreme dehydration without serious effect.
– Low metabolic rate reduces need for water
– Ability to recycle urea when food protein is limited
– Produces little urine and dry faeces
– Rests all day in same place to avoid exertion
– Wide range of plants eaten eg. Can utilize thorns, dry vegetation and saltbush that other animals avoid
– Samples plants over a wide area and therefore doesn’t overgraze areas and destroy all vegetation.
– can go for long periods without water therefore can graze on pastures far from wells.
– Can drink large quantities of water in short time, eg. can drink 180 litres in 24h, therefore spends minimum time at usually overgrazed areas.
– a lean camel can survive a body water loss of 40% of its body weight (man is near death if he loses 12% of body weight.)
– in normal conditions water in plasma of man and camels is 16%, but if a camel losses 25% of body water blood volume drops by less than 1/10, whereas under same conditions in man blood volume drops by 1/3 and blood volume becomes too thick to carry heat to body surface to be dissipated.
– Skin capillaries have thick walls and narrow lumina thus preventing loss of water from blood vessels.
– Diurnal rise in body temperature in hot weather to conserve water. When air temp goes up during the day, body temperature can rise 4-5C and camel does not need to sweat to bring temperature down, therefore conserves water. Also when temperature drops at night then camels temperature can drop without it having to shiver and use energy to keep warm.
– Heat can be stored in the body therefore water need not be dispersed by evaporation to cool the body down.
– oval shaped and small but numerous
– high affinity for O2 so can take up more O2 that other animals per unit volume of cells
– narrow wideth enables them to move around even when animal dehydrated and blood viscosity increased.
– Can swell up to 240% of initial size without breaking even after drinking lots of water.
– have long “loops of Henle” and therefore can absorb more water
– 5 – 7 litres of highly concentrated urine produced/day if the animal is grazing green fresh grass, only half that amount produced in the dry season.
– If goes one day without drinking less than 2.8L of urine excreted in 24h
– Excretes small amounts of urine
– Urine has a concentration of salt twice that of seawater
– long legs to cover large areas in search of food
– long neck enables it to reach twigs and leaves 3.5m above ground, out of reach of smaller animals.
– adapted to excessive light an protected from sand
– protected by thick long eyelashes
– are arrhythmic, as they can see by day and by night
o (at night uses choroidal tapetum to enhance vision)
o (by day fringed margins of iris protect pupil by only letting in little light.)
– eyelids somewhat transluent so that camel can walk with eyes shut.
– Has constant large flow of tears to keep eyes from drying out.
– nostrils that can close to keep out sand
– have cavities where inspired air is moistened and exhaled air cooled reducing water loss.
– camels often grasp vegetation between their long hairy lips, the upper two halves of which are separated and move independently enabling it to pick of leaves and fruit from trees.
– hard pad on top jaw. Incisor and canine teeth continue to grow throughout lifetime so a diet of some hard plant parts or even sometimes dried meat and bones are essential to keep teeth down.
– Hump is stored fat not water.
– Some water produced from oxidation of fat but also this process requires O2 from respiration and whilst O2 is breathed in, air saturated with water is breathed out so more water lost than gained from this.
– If food is plentiful then the hump is large, if camel in poor condition then hump is small.
– Because fat not stored subcutaneously, this means that heat can readily flow to body surface and be dissipated.