Lizards

Seven families of lizards are native to Arizona. Many can be found throughout Montezuma Castle and Montezuma Well during the hotter months of the year. The most common lizards are whiptails and spiny lizards. Please do not handle or harass any lizard you may find.

Whiptail Lizard (Aspidoscelis spp.)

Whiptails are one of the most common types of lizards seen in the park and one of the most interesting! There are four species of whiptail lizards found in the park, and three of those species (the desert grassland whiptail, plateau striped whiptail, and Sonoran spotted whiptail) are only female. These species reproduce through a process called parthenogenesis and all hatchlings are clones of their mother. Many other whiptail species are entirely female as well. Whiptails are a medium-sized lizard that occupy a wide variety of habitats including wind blown sand dunes, creosote flats, rocky hillsides, and canyons.

Spiny Lizards (Sceloporus spp.)

Both Clark's and desert spiny lizards are found in the parks and are some of the largest lizards found in the Verde Valley. Spiny lizards are large, heavy-bodied lizards with sharply pointed, overlapping scales and their bodies can measure over 5 inches long. Males are larger than females and more brightly colored, with males of both species having deep blue scales on their bellies and black patches on their throats. When encountered, they will often flee into a crevice or to the opposite side of the tree trunk. During the day, they can be seen hunting ants, beetles, caterpillars, and other insects. They are often seen on trees, packrat nests, woodpiles, fences, and rock piles.

Gila Monster (Heloderma suspectum)

This lizard is the largest native lizard in the United States and a member of the only family of venomous lizards in the world. Gila monsters are generally found in central and southeastern Arizona. Although found in the Verde Valley, they spend about 90% of their time underground, so it is very rare to see one in the wild. They are efficient nest raiders and feed on bird and reptile eggs as well as small animals and carrion. Males agressively fight each other for access to females in matches that can last for several hours.

Gila monsters are not aggressive toward humans and only bite when provoked. Venom produced in their lower jaw is chewed into prey (or potential predators). A Gila monster's bite is extremely painful.

Gila monsters were the first venomous reptile to be protected in the United States and it is illegal to handle, collect, or kill them throughout their entire range in the US and Mexico. They are listed as "near threatened" on the IUCN Red List.

Greater Earless Lizard (Cophosaurus texanus)

One of the smallest lizards in the park, earless lizards get their name from the fact that they do not have external ear openings. They are often seen in relatively flat, open, and sparsely vegetated areas with sandy or gravelly soil. This lizard is a diurnal ground-dweller that is most active in mornings and evenings during the hotter months and active all day during spring and early fall. They eat insects, spiders, and hatchling lizards. In other parts of their range, they are easily confused with the elegant earless lizard.

Ornate Tree Lizard (Urosaurus ornatus)

Found in Arizona's biotic communities from the low deserts through Petran Montane Conifer Forest. Commonly observed on urban walls, fences, and building exteriors. Natural habitat includes trees, boulders, cliff faces, and rock outcroppings. These lizards mostly eat insects and spiders.

Eastern Collared Lizard (Crotaphytus collaris)

These brightly colored lizards are found across most of Arizona, the southern-central US, and into Mexico. Adult males are unmistakable among the lizard species found in the Verde Valley. They are often seen basking atop large rocks, although they are uncommon at Montezuma Castle. They use their powerful jaws to capture snakes, smaller lizards, insects, and spiders. Collared lizards are famous for their ability to sprint on their hind legs and can run up to 16 miles per hour. This behavior is usually reserved for escaping predators.