The Desert iguana (Dipsosaurus dorsalis) is one of the most common lizards of the Sonoran and Mojave deserts of the southwestern United States and northwestern Mexico. They also occur on several Gulf of California islands.

The Desert iguana is a blunt medium-sized lizard. Including the tail, these blunt-headed lizards typically grow to 16" (40 cm). They are pale gray-tan to cream in color with a light brown reticulated pattern on their backs and sides. Down the center of the back is a row of slightly-enlarged, keeled dorsal scales that become slightly larger as you move down the back. The reticulated pattern gives way to brown spots near the back legs, turning into stipes along the tail. The tail is usually around 1 1/2 times longer than the body from snout to vent. The belly is pale. During the breeding season, the sides become pinkish in both sexes.

Their preferred habitat is largely contained within the range of the creosote bush, mainly dry, sandy desert scrubland below 3300 ft. It can also be found in rocky streambeds up to 3300 ft. In the southern portion of its range this lizard lives in areas of arid subtropical scrub and tropical deciduous forest.

These lizards can withstand high temperatures and are out and about after other lizards have retreated into their burrows. They burrow extensively, and will often climb into shrubs for shelter and defense. Their burrows are usually constructed in the mounds of sand that accumulate around the bases of bushes like the creosote. They also often use ready-made burrows of kit foxes and Desert tortoises.

Mating takes place in the early spring. It is belived that only one clutch of eggs is laid each year, with each clutch having 3-8 eggs. The hatchlings appear around September.

Desert iguanas are primarily herbivorous, eating buds, fruits and leaves of many annual and perennial plants. They are especially attracted to the yellow flowers, especially those of the creosote. They have also been reported to eat insects, feces (mammal and lizard) and carrion.

These lizards are very quick, and can often be seen running across the road just ahead of oncoming cars. At high speeds they run on their powerful back legs, folding the front legs into their body.

Predators of these iguanas are birds of prey, foxes, rats, weasels, some snakes, and people. Their eggs are also eaten by many animals.

The scientific name comes from Greek for "thirsty lizard" (Dipsa, "thirst(y)", and sauros, "lizard"). The name "dorsalis" is probably a reference to its well-defined dorsal crest.

References

• Arizona-Sonora Desert Museum
• Death-valley.us article on the Desert Iguana
• San Diego Natural History Museum
• Frost, D.E. and R.E. Etheridge (1989) A Phylogenetic Analysis and Taxonomy of Iguanian Lizards (Reptilia: Squamata). Univ. Kansas Mus. Nat. Hist. Misc. Publ. 81
• Frost, D.R., R. Etheridge, D. Janies and T.A. Titus (2001) Total evidence, sequence alignment, evolution of Polychrotid lizards, and a reclassification of the Iguania (Squamata: Iguania). American Museum Novitates 3343: 38 pp.