Juvenile Chuckwalla Creative Commons

Arizona Chuckwalla

The Chuckwalla, sometimes called "Chuckawalla" is the second largest lizard in the United States, second to the Gila Monster.

Unlike the Gila, the Chuckwalla is not venomous. Although there are other species, the "Common Chuckwalla"' is primarily found in the southwestern desert areas including the Mojave Desert in California and the Sonoran Desert of Arizona. They are also found in Sonora, Mexico close to the Arizona border.

Although they look ferocious, the Chuckwalla is docile and timid. They are harmless to humans and will run and hide when threatened. They hangout near tight rock crevices and when in danger, they squeeze into those crevices and inflate their bodies to thoroughly entrench themselves. When embedded, the only way to get them out is to disassemble the rock formations.

Characteristics and Behavior.

Chuckwallas are distinguished with wide and flat mid sections and have a prominent paunchy belly. Their tails are thick and taper to a blunt tip. They have loose folds of skin around the neck and sides of the body. An adult male reaches an average total length of 16 to 18 inches and weighs about 2 pounds. The female Chuckwalla is noticeably smaller than the male.

Male Chuckwalla Creative Commons

The male has more colorization than the female. They have a black head, forelegs and upper trunk with either a reddish-yellow or bright red body while the female is grayish brown with little pattern. Young Chuckwallas are distinguished with a dark background color with yellow bands around the body extending to its tail.

Chuckwallas emerge from the safety of rock crevices in the morning and bask in the sun to reach a body temperature of 100 to 105 degrees before searching for food. They are basically "herbivorous" eating fruit, leaves and flowers as well as an occasional insect.

Its predators include coyotes, bobcats, hawks and owls. Chuckwallas hibernate during the colder winter months and emerge during February when warm weather begins to return.

Mating season generally runs from April to July with females laying 5 to 16 eggs that typically hatch in late September. Chuckwallas can have a lifespan of 25 years and longer.