|Like it or not, the heat is a fact of life in the Sonoran Desert, the hottest desert in North America. Most forms of life resist the extreme temperatures--and extreme they are. A person stripped of clothing, water, and shade in the morning could be dead by evening.|
How do desert plants and animals survive? Many become creatures of the night, as depicted in the accompanying foldout. The saguaro cactus develops an intricate, shallow root system that allows this desert giant to absorb and store up to 760 liters of water. The kangaroo rat recycles and retains water so that very little moisture is lost through urination. Birds ride warm currents of air to find relief at great heights. The spadefoot toad burrows deep into the ground for a period of estivation (a state akin to hibernation), while lizards migrate back and forth from sun to shade. Cicadas extract water from their blood and transport this water through large ducts to the surface of their body, where it evaporates.
Despite the heat, the Sonoran Desert is considered by many to be the most beautiful North American desert. With more than 2,500 species of plants, it is the most botanically diverse desert, providing abundant food sources for animals. Despite the torrid temperatures, the Sonoran is a magnet for the millions of people surrounding this region who are attracted by its rich natural resources and open spaces. Encompassing 312,000 square kilometers, the Sonoran Desert is spread across Mexico and the United States. It is one of the four North American deserts, along with the Great Basin, the Mojave, and the Chihuahuan. Much of this vast area receives less than 2.5 centimeters of rainfall each year, but its higher elevations, which exceed 2,100 meters, receive as much as 38 centimeters.
By Richard Brook, Gary Stumpf, and Mary Tisdale