How would you like to bask in the desert sun beneath towering sandstone cliffs alongside a lush, riparian waterway? You won’t be alone. Joining you will be a myriad of reptiles; ectotherms that soak up the sun to warm up internally and get moving. While in Zion National Park, you may have the opportunity to spot one of 16 species of lizards lazing in the sun or witness the sly moves of one of 13 slithering snakes. If you are very lucky, you may even spot the slow, persistent movements of the federally protected desert tortoise.
Zion is home to a variety of interesting lizard species, each with unique adaptations and curious behavior. Look for smaller lizards alongside Zion’s trails early in the morning. The smaller the lizard’s surface area, the quicker the body can warm up to move quickly. Larger lizards will begin to bask later in the morning once the sun’s rays are more powerful. This prevents large lizards from becoming prey before they have enough energy to safely scurry away from predators.
The plateau lizard is the smallest lizard of Zion,with distinctive patches of blue along its belly. This is Zion’s most common lizard, often seen along the trails in Zion Canyon. The plateau lizard has a wide range of food sources from moths and beetles to butterflies and wasps.
Greater Short-horned Lizard
Another lizard small in stature is the short-horned lizard. This lizard has distinctive horns, or spines, which are modified epidermal scales. These scales make the lizard very unappetizing to predators, with the exception of the roadrunner. These curious birds orient the lizard’s scales away from their vital organs during swallowing to ensure safe digestion. In addition to its scales, the Greater Short Horned Lizard uses blood as a defensive mechanism. The lizard has the ability to project blood from its tear ducts up to 3 feet from its body. Losing blood is detrimental to the lizard's health as it will need to regenerate the blood lost.
Western Whiptail Lizard
A large lizard commonly seen in Zion Canyon is the western whiptail. Look for its long lean physique and rusty orange coloration on the sides of its back. Look quick though, this lengthy lizard can sprint up to 9-10 miles per hour.
Great Basin Collared Lizard
Also large and surprisingly quick is the carnivorous Great Basin collared lizard. Known to stand up and run on its hind legs, this 14-inch lizard preys upon smaller lizards, snakes, and insects. Look for the collared lizard in the lower canyon and along the Watchman Trail.
Unlike most lizards, many of Zion's snakes are nocturnal, so consider yourself lucky if you have a snake sighting. Many snakes have evolved to be efficient nighttime predators. When snakes are moving along the ground, their long, slender bodies, in full contact with the earth, can detect vibrations. This helps them "hear" the movements of their prey approaching. A forked tongue, when flicked, helps the snake detect odors and heat, while other snakes have developed sharp eyesight.
Snakes are exclusive carnivores and in the desert will often rely on their prey as both a source of food and water.
Great Basin Rattlesnake
The great basin rattlesnake, Zion’s only venomous snake, can go for months without water. The snake is well adapted to the desert and gains most of its hydration from food it digests. Average strike speed for the great basin rattlesnake is 9.6 feet per second. Like other rattlesnakes, you can usually identify them by the triangular head and the rattle at the end of their tail. However, the rattles are not always present—they can break off, or a young snake may not have developed their rattles yet. Locally, great basin rattlesnakes are usually light brown with darker brown blotches down the middle of their back. However, their colors can vary over a range of shades, and they usually blend in well with their surroundings.
Immune to rattlesnake venom, the common kingsnake is an occasional predator to the rattlesnake. This snake uses its powerful black and white banded body to tightly constrict its prey, which often includes other snakes and small mammals. Look for the kingsnake in low elevations and sandy washes.
The striped whipsnake is a skilled tree-climber. This snake retreats to tree limbs, high off the ground, in search of prey such as lizards and birds. In Zion, one should search high and low if you’re seeking wildlife observations.
A rare reptile sighting in Zion is the desert tortoise. This long-lived tortoise is a resident of the Mojave Desert, which extends north into the southern-most portions of Zion. The desert tortoise population is threatened because of high predation rates, habitat loss, illegal collection, and vehicle collisions. If you see a tortoise in Zion, simply watch it from a distance and enjoy the experience.
Whether you see the desert tortoise in the low elevations or the short-horned lizard high on the plateau, Zion’s reptiles can be found at every elevation in the park during the spring, summer, and fall. All of Zion’s reptiles are known to brumate for four to five months a year. During this time, reptiles burrow down in the ground from depths of four inches to eight feet. Reptiles will come out of brumation on a warm sunny day in the middle of winter, then go back to brumation once it starts to cool off again. Once spring arrives in Zion and temperatures begin to rise, be sure to keep an eye out for Zion’s great diversity of reptiles.