Hear the words “Death Valley” and an image of an uninhabited landscape might come to mind. Below-sea-level basins are ravaged by drought and heat, receiving less than two inches of rain per year. Temperatures soar above 120 degrees. While these conditions may seem harsh to humans, Death Valley is home to a great diversity of wildlife. Hard-learned, clever adaptations enable desert animals to thrive in this unlikely place.
Death Valley is one of the driest places on earth. Habitats with fresh water can be difficult to find, so some desert animals have evolved to simply drink less water. Roaming through mountains and canyons, bighorn sheep are able to go without water for several days and can lose up to a third of their body weight due to dehydration. When water becomes available again, the sheep can drink several gallons at a time to rehydrate.
Like bighorn sheep, kangaroo rats do not have to worry about dehydration. In fact, they are so perfectly adapted to arid environments, they do not need to drink water their entire lives! They can survive on water digested from their seedy, vegetarian diet. Kangaroo rats conserve their body’s precious water by releasing wastes in very concentrated urine and dry feces.
While finding enough water is a challenge, coping with the fierce summer heat is a constant concern for desert inhabitants. The desert tortoise is a champion of avoiding the heat. Unable to regulate its own temperature, the tortoise spends most of the year in its burrow. Underground, it is protected from extreme weather. During the hottest times, tortoises estivate, or enter a state of dormancy that allows them to conserve energy and save water. Additionally, desert tortoises survive frigid winter temperatures by hibernating. Depending on the weather, desert tortoises might be active above ground for only three months of the year!
Rather than “sleep” through most of the year, many animals rest during the hot summer days and are active at night. Nocturnal wildlife leaves behind clues on sand dunes. For example, you may find coyote tracks alongside those of a jackrabbit. The rabbit’s tracks zig and zag across the sand while the long strides of the coyote’s tracks portray a fast run. Hunting during the cool nights and early mornings allows the coyote to spend more energy catching prey. The cover of darkness also helps the jackrabbit hide from potential predators.
While there are advantages in being nocturnal in the desert, there are still creatures who brave the daytime heat. Commonly seen animals have specific physical adaptations which allow them to be out in the heat longer. Roadrunners, for instance, can operate in the heat of the day because their body temperatures are naturally high (104 degrees).
The jackrabbit, another common desert creature, stays cool by releasing heat from its over-sized ears. When the rabbit retreats into the shade, warm blood from its core circulates through blood vessels in its ears, where heat is lost to the surrounding air.
Last updated: January 17, 2021