Observant hikers on Phoenix desert preserve will quickly notice skittering lizards, zipping hummingbirds and the occasional snake that call the desert home. Chuckwallas are large bodied lizards that bask throughout the hottest summer months and wedge themselves into cracks when they feel threatened. Rattlesnakes and bullsnakes often emerge in the early morning or early evening during warm months and should be enjoyed from a distance.
Below we've listed some of the most common desert critters found in Phoenix desert preserves. Remember, the preserve is their home, and when visiting, please enjoy their beauty from a safe, courteous distance. It is unlawful to move, touch, harm, or remove any wildlife from the preserves at any time.
The Desert Tortoise is an herbivore that may attain a length of 9 to 15 inches in upper shell length. At least 95 percent of its life is spent in burrows. There it is also protected from freezing while dormant from November through early spring. They eat primarily herbs, grasses, shrubs, cacti, and flowers. Ravens, Gila Monsters, Foxes, Roadrunners and Coyotes are all natural predators of the Desert Tortoise. This handsome specimen shown at right was seen lumbering along a roadside in South Mountain Park. (Click on image to enlarge detail)
Chuckwallas call all Phoenix preserves home, but South Mountain Park is notable for its chuckwalla population. With an average of 65 chuckwallas per hectare, South Mountain has among the highest density of chuckwallas in the Sonoran Desert. And South Mountain chuckwallas are like none other -- they exhibit a “carrot tail” phenotype, which is unique to this population. Strictly herbivorous, the Chuckwalla reptile eats fruit, leaves, buds and flowers. When the Chuckwalla senses danger, it scurries between rocks and lodges itself tightly in crevices by inflating itself. They have a thick blunt tail, and grow 11 to 18 inches long. These lizards emerge in the morning and bask in the sun until it reaches its optimum body temperature of 100 to 105 degrees.
(Click on image to enlarge detail)
Venomous! Speckled rattlesnakes are common in Phoenix preserves and other parts of the valley adjacent to similar rocky hillside habitat. They are highly variable in color, from a white/grey in the South Mountain and White Tanks areas, brown in North Phoenix, and orange and red going North into Cave Creek and the Anthem areas. They have a loosely banded pattern that is highly flecked to resemble granite. The Southwestern Speckled Rattlesnake is a medium sized snake, normally around 3 feet long, but has been known to exceed 4 feet. (Click on image to enlarge detail)
Seldom seen but of great importance are the numerous bat species that live among the desert cliffs and caves of our mountain parks. Bats are a key pollinator of the saguaro cactus and other night blooming plants. They favor nectar, pollen, flowers and fruit from agave and other cacti, especially saguaro. They can be observed during dusk and returning to their roosts in the early morning.
(Click on image to enlarge detail)
Western Diamondback Rattlesnake
The Western Diamondback Rattlesnake, which can exceed 7 feet in length, is the king of Southwestern desert rattlers. Its basic color ranges from brown to gray to pinkish. Its back is lined with dark diamond-shaped blotches outlined by lighter-colored scales. Its tail is circled by several alternating black and white bands. This snake takes up residence among communities of small mammals such as rabbits, ground squirrels, mice and rats; usually hunting at night. The Western Diamondback, especially the juvenile, often comes under attack itself. It may become a meal for an eagle, a hawk, roadrunner, kingsnake or whipsnake, coyote, or fox. (Click on the Diamondback image to enlarge)
References & Related Links:
Arizona Game and Fish
Reptiles of Arizona
International Journal of Organic Evolution: Kwiatkowski M.A, and Sullivan B.K. 2002. Geographic Variation in Sexual Selection Among Populations of an Iguanid Lizard, Sauromalus Obesus. Evolution 56(10): 2039-2051.Author Information:
1 Department of Biology, Arizona State University, Tempe, Arizona 85287-1501
2 Department of Life Sciences, Arizona State University West, 4701 West Thunderbird Road, Glendale, Arizona 85306
Common Snakes of the Phoenix Area,
Arizona Office of Tourism Guide http://www.arizonaguide.com/things-to-do/nature/birding-wildlife/arizona-wildlife-viewing
Arizona-Sonoran Desert Museum