Every animal has internal organs and physiological processes such as digestion and blood flow that let them survive in their habitat. Often these habitats have harsh conditions that require especially interesting physiological adaptations.
Arabian Oryx: The Desert Antelope
For example, the rare, endangered Arabian oryx is an antelope that thrives in the deserts of the Arabian Peninsula, where shade temperatures can exceed 120 degrees Fahrenheit. Its adaptations to extreme heat and a lack of available water include:
• Living for weeks without water by obtaining most of its moisture requirements from the desert-scrub plants it eats.
• Turning its stored fat into water as a metabolic byproduct.
• Having a high tolerance for dehydration.
• Excreting concentrated urine and dry feces, reducing water-loss to the environment.
• Minimizing its overall activity during the day during the hottest seasons of the year. This adaptation reduces the amount of water the oryx requires.
• Involuntarily reducing its daytime sweat production by tolerating a high body temperature.
How Do Giraffes Avoid Fainting?
When the amount of blood flowing to your brain is reduced you run the risk of fainting. Fainting is nature’s way of lowering the height of the head and increasing the amount of blood going to the brain.
Then, how do giraffes manage to pump enough blood from its heart, against gravity, more than six feet up to its brain?
It has exceptionally high blood pressure. If a human had a giraffe’s blood pressure it would be dangerously high and probably fatal. A giraffe can tolerate high blood pressure because it has these adaptations:
• Although it has a surprisingly small heart, the heart muscle is very thick and strong.
• It has thick blood vessels, and as a giraffe grows, its blood vessels thicken along with the increasing length of the neck. This prevents high blood pressure from breaking through the vessels.