Many animals have adapted to avoid the hot daytime temperatures. These nocturnal animals hunt and eat at night. Other animals choose to stay in the shade. For example, jackrabbits follow the shadows of larger objects such as cacti and shrubs.
Physical Evolution
In order to withstand the harsh climate, many animals have evolved body parts which are key to their survival.
Kangaroo Rats The kangaroo rat has evolved in the following ways: • Its colour allows it to camouflage itself in its surroundings.
• It has smaller front feet that allow it to handle food and dig burrows with its sharp claws.
• Its longer back feet allow it to leap away quickly from predators. As it leaps away, it often flicks sand behind it to blind predators.
: Fig. 28.11 A kangaroo rat
• Its long tail acts as a balance while jumping and allows it to quickly change direction by using it as a brake in the sand.
Camels
The camel is the best-known example of an animal that has adapted to suit the desert environment. Its suitability for such a climate has earned it the name of ‘Ship of the Desert’.
• Camels have two rows of long eyelashes, which prevent sand from getting in their eyes. They also have an inner eyelid to protect their eyes during sandstorms.
• Camels can tighten their nostrils during sandstorms to ‘filter’ out the sand as they breathes.
• Camels have thick coarse fur which protects their backs from the intense sunlight. Their under belly is covered in wool which protects it from the scorching sand beneath it.
• Camels store fat in their hump(s), which acts as an effective food reserve. This fat can be converted into water during times of drought.
(a)
Stretchy nostrils: keep out the sand
Long eyelashes: help to keep sand out of eyes
(b) Hair on back to protect against sun
Leathery mouth: helps camel eat spiky plants
Long legs: keep
camel off the hot sand: help to keep cool
Padded feet: stop camel sinking into the sand and to protect from heat of the ground
: Fig. 28.12 (a) Camel adaptations and (b) a herd of camels
GEOECOLOGY 559
Hump for storing food
GEO DICTIONARY
Predator: an animal that hunts and eats other animals
