The lizard is generally docile. But when agitated, it can grip with its teeth for as long as several minutes, leaving a painful bite and a good dose of venom, which can make you very sick. The Gila monster is found only within the Sonoran Desert and it is near its eastern limit in the San Pedro River valley. Although its range extends south to central Mexico, in the southwestern states the Gila woodpecker is a bird of the Sonoran Desert. That means it uses its sturdy bill and powerful muscles to excavate holes, for nests, in tall Saguaro cacti, as well as several types of trees.
Gila woodpeckers are omnivores, feeding on insects, nectar, fruits and berries, and invertebrates.
Other cavity-nesting birds, such as kestrels, owls, and flycatchers, often use the Gila woodpeckers' cavities for their own nests. The beautiful scaled quail is a bird typical of the Chihuahuan Desert, in north central Mexico. Higher and cooler than the Sonoran Desert, the Chihuahuan is rich in arid grasslands, which provide cover and nesting sites for these birds. The scaled quail builds its nest on the ground, and although they can lay more than a dozen eggs, their breeding success varies depending on rainfall. The San Pedro River valley has grassland habitat and healthy populations of scaled quail living close to their western range limit.