Reptiles

Colorful collared lizards are often seen during Summer months.

NPS/Marge Post

Well-adapted to the often dry environment of Petrified Forest National Park, reptiles play an important part in maintaining the health of the ecosystem. Over sixteen varieties of lizards and snakes make Petrified Forest their home. Reptiles occupy a variety of habitats ranging from grassland to rocky slopes. They consume large quantities of insects, spiders, scorpions, other reptiles and small mammals thereby preventing infestations of any single species. Respecting the entire reptile community helps to preserve this vital link.

All reptiles are "ectothermic," or cold-blooded, regulating body temperature via external sources rather than internal metabolism. The metabolic rate of a reptile is very low, but so are its energy needs. Keeping warm in the Arizona sunshine does not require much work, so energy generated can be used for reproduction and finding food instead of for heating and cooling. Of course, there are limitations to this type of adaptation. Since they cannot pant or sweat, reptiles are not able to endure extremely high temperatures without shade. They also cannot endure freezing temperatures. When it is cold, they hibernate or enter into an inactive torpor.

When lizards are seen scurrying across a rock or path, please resist the urge to catch them. Lizards can have a mean bite and some will actually shed a tail to escape capture. Though the tail will grow back, a great deal of body energy is used in the process and population dynamics will be affected. Enjoy them from a respectful distance.

The following is a list of the reptiles known to occur in the park. Help protect this important park ecosystem by observing our reptile inhabitants from a distance.

 

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New Mexico Whiptail (Aspidoscelis neomexicanus) are parthenogenic (“all moms, no dads”) but their DNA changes each generations unlike other species that reproduce this way.

 

NPS/Andy Bridges

The Pai Striped Whiptail (Aspidoscelis pai) is a beautiful, sleek lizard. The length is accentuated by the long narrow strips and that turquoise tail. This species is very similar to the Arizona striped whiptail (A. arizonae), and endemic to Arizona in the United States.

 

Plateau Striped Whiptail (Aspidoscelis velox) is another parthenogenic species. Some whiptails are mistaken for skinks but are more slender and not as glossy.

 

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Did you know that out of all the lizards in the world, a small percentage are bipedal? At least in short bursts: the Collared Lizard (Crotaphytus collaris) runs on its two back legs to get away quickly. Studies have shown that it isn’t that two legs are faster than four, it’s that they can accelerate quicker. They look like colorful, mini dinosaurs when startled into a bipedal race away from danger!

 

NPS/Andy Bridges

A handsome little reptile, the Common Lesser Earless Lizard (Holbrookia maculata) is found throughout northern Mexico, central and southwestern U.S. The color of this lizard often relates to the surrounding soil and/or rocks where it perches. Gravid females often have a pinky peach tone and orange throat.

 

NPS/Andy Bridges

Sometimes misnamed a horny toad, Greater Short-horned Lizard (Phrynosoma hernandesi) is a reptile, not an amphibian. Its wide, flat body is armored and spiked as well as camouflaged to blend into its gravelly surroundings. One of the most unusual deterrents to predators is its ability to squirt blood from its eyes, particularly irritating to canids like coyotes and foxes.

 

NPS/Lauren Carter

Did you know that lizards can lose their tail as a means to escape a predator? This is caudal autotomy. Along the tail are several weak spots called fracture planes where the tail can detach without bleeding. The loose appendage wiggles around, attracting the attention of the attacker. The new tail often contains cartilage instead of bone and can have a different texture and hue. While the loss of the tail probably saved the lizard’s life, it really messes up its social status and sometimes mating ability. This Sagebrush Lizard (Sceloporus graciosus) did lose its tail but has nearly finished regrowing a very decent replacement. Not all are as nice.

 

NPS/Hallie Larsen

Plateau Fence Lizard (Sceloporus tristichus) is typically out sunning on a warm day but begins to hibernate at this time of the year. The pretty chevron patterns on its back are made up on pointed and keeled scales, helping it to blend into its surroundings. They can be a favorite snack of a roadrunner. These lizards prefer small insects and other arthropods for lunch. Credit NPS/Hallie Larsen.

 

NPS/Andy Bridges

Common Side-blotched Lizard (Uta stansburiana) is a beautiful little lizard. Male side-blotched lizards compete for mates with a fascinating strategy that researchers liken to rock-paper-scissors. There are three types of males, with orange, yellow or blue throats. Oranges are larger, more aggressive, and have large territories with several females. Blues have smaller with just one female and blues cooperate for defense. Yellows are “sneakers” mimicking females, they don’t have territories and sneak into other males’ space to mate with their females, especially oranges as most blues fend them off. It’s been noted that some areas don’t have all the colors.

 

NPS/Andy Bridges

Glossy Snake (Arizona elegans) is a non-venomous endemic to the southwestern United States and Mexico. It resembles a faded gopher snake and so is also sometimes mistaken for a rattlesnake but tends to be smaller (about a yard in length on average), slender with a narrow head. If caught, it vibrates its tale and has a stinky musk. This is a gentle, pretty snake.

 

NPS/Andy Bridges

Prairie Rattlesnake (Crotalus viridis) are relatively light-colored vipers with the broad head. While venomous, an adult will rarely inject poison into a person as we are not their prey. Pay attention if you hear that buzzing rattle. They are warning you to leave them alone. They can get over a yard or meter in length.

 

NPS/Andy Bridges

Chihuahuan Nightsnake (Hypsiglena jani) is rear-fanged and mildly venomous, although not dangerous to people. This nocturnal snake is a hunter of lizards, smaller snakes, and sometimes soft-bodied insects.

 

NPS/Hallie Larsen

California King Snake (Lampropeltis californiae)—like other kingsnakes—is equipped with an enzyme to break down the venom from poisonous snakes. Why? It eats poisonous snakes including rattlesnakes! This is an unusual occupation among snakes. It is a beautiful creature as well!

 

NPS/Andy Bridges

Striped Whipsnake (Masticophis taeniatus) is a long, slender non-venomous snake. The dark body is lined with pale stripes. Its name is perfect as it often evades predators—and photographers—with whip-like speed. They are diurnal hunters.

 

NPS

Gopher Snake (Pituophis catenifer) is a common, non-venomous snake. It can get quite large but uses mimicry to baffle predators. With a shake of its tail tip and puffing up its throat, the gopher snake pretends to be a rattlesnake.

 

Reptiles
New Mexico Whiptail (Aspidoscelis neomexicanus)
Pai Striped Whiptail (Aspidoscelis pai)
Plateau Striped Whiptail (Aspidoscelis velox)
Eastern Collared Lizard (Crotaphytus collaris)
Western Earless Lizard (Holbrookia maculata)
Greater Short-horned Lizard (Phrynosoma hernandesi)
Common Sagebrush Lizard (Sceloporus graciosus)
Plateau Fence Lizard (Sceloporus tristichus)
Common Side-blotched Lizard (Uta stansburiana)

Glossy Snake (Arizona elegans)
Prairie Rattlesnake (Crotalus viridis)
Chihuahuan Nightsnake (Hypsiglena jani)
California King Snake (Lampropeltis californiae)
Striped Whipsnake (Masticophis taeniatus)
Desert Striped Whipsnake (Masticophis taeniatus ssp. taeniatus)
Gopher Snake (Pituophis catenifer)