by Lilia Leung
Over 80% of Niger’s land mass lies in the Sahara Desert, an arid region with an annual rainfall of a few inches or less. All animals on earth require water to survive, but desert animals have evolved the incredible ability to survive in hot, dry climates by making the best use possible out of the limited water supply. Let’s take a look at some of these desert animals and the characteristics they have developed through years of evolution that have allowed them to survive in arid climates.
The first desert animal that comes to mind is the camel. Contrary to popular belief, camels do not store water in their humps. Rather, fat is stored in the humps, which allows camels to efficiently regulate their body temperature. The concentrated fat is also useful for the long, grueling days when food is scarce and the extra fat could easily be metabolized for an energy boost. Camels have also evolved the ability to excrete less water in their urine when water is scarce, and to only start sweating when temperatures reach 105ºF, allowing them to conserve more of the water in their bodies for later use.
Desert Kangaroo Rat
The desert kangaroo rat is a desert animal that makes efficient use of the water they produce through metabolic processes. As their diet, kangaroo rats eat insects and various parts of the plants, including seeds, stems, buds, fruits, and leaves, all of which they could extract water from. The kangaroo rat’s kidneys are also able to produce concentrated urine, allowing them to rid their bodies of waste without expelling too much water. In addition, desert kangaroo rats have long nasal cavities that help cool the air as it’s being exhaled, allowing it to be condensed into moisture and reabsorbed into the body. All of these body mechanisms allow the kangaroo rat to survive on limited amounts of water.
Inactivity prevents water loss, so desert tortoises heavily regulate their activity and body temperature for the purpose of water conservation. They are the most active during rainy seasons and are less active for the remainder of the year. Desert tortoises also try to seek out the optimum habitat for water conservation. Aside from the rock shelters and pallets that they find, desert tortoises are also able to dig burrows for themselves during inactive periods. In addition to being sheltered from extreme weather conditions, the burrows hold moisture that helps tortoises from becoming dehydrated too quickly. Tortoises are also able to water in their bladders, which has permeable walls. During dry seasons, the stored water can be reabsorbed for hydration purposes.
Other amphibians like the Australian water-holding frog and the Gila monster have similar characteristics.
The thorny devil is native to the sandy areas of Australia and is so named because of the numerous spikes on its head and body. The thorny devil is able to absorb any moisture that comes in contact with its skin via the hygroscopic grooves between the spikes, and the moisture is then drawn into its mouth through the process of capillary action. Just like other desert amphibians, thorny devils lie low in the extremely warm months and the extremely cold months by hiding in underground burrows.
While many desert animals are restricted to certain areas because of the availability of clean water, other desert animals are able to travel in search of clean water. Recently, a researcher conducting research in Namibia has found that some bat species residing around the area of the Namib Desert not only travel in search of food, they are also willing to fly great distances to search for high-quality water, in particular, water with low salinity. People living in the same area as these bats may take advantage by tracking these bats to find sources of clean water.
While we humans have not evolved the ability to use our bodies as water storage, there may be unobtrusive ways for us to take advantage of other animals’ abilities to find fresh, sanitary water. Unfortunately, the continuous change in our planet’s climate is both taking a toll on our natural resources and reducing the number of animal species on earth. The kindness we must have towards our planet and our fellow earth inhabitants are ever more important now in the face of this looming crisis.