Reptile and Amphibian Guide

This guide initially displays common reptiles and amphibians of all shapes. Use the selectors below to view particular shapes, include rare species, or search by name.

Reptiles are a group of vertebrate animals that are cold-blooded, i.e., they regulate their inner body temperature by responding to the temperature of their environment, basking in the sun to warm themselves up or lying in the shade to cool off. Animals in the class Reptilia include snakes, lizards, crocodiles, turtles and tortoises. All of these creatures are covered in scales and breathe air through their lungs throughout their lifetime. In addition, they all produce eggs. Most reptiles lay eggs from which young hatch directly after an incubation period. However, some snakes, including rattlesnakes, carry their eggs internally and then give birth to live young.

Like reptiles, amphibians (frogs, toads, newts, salamanders and worm-like caecilians) are cold-blooded vertebrates. However, unlike reptiles, animals in the class Amphibia do not have scales but rather have skin that is permeable so that molecules and gases can pass through it. In addition, they lay their eggs in water where the young are born as larvae using gills to breath. The larvae grow and change into the adult form. This process includes developing lungs thus allowing the adults to live on land. Amphibians are considered to be the link between fish and reptiles as they were the first animals to leave the water and come onto land.

The question often arises of how to tell the difference between a frog and a toad. Although they are closely related amphibians, there are some features that can be used to distinguish them. Frogs have long hind legs for jumping, moist and usually smooth skin and bulging eyes. In addition, they typically stay in water. Toads have short legs for walking and hopping, dry and bumpy skin and do not have bulging eyes but do have poison glands behind their eyes. They mostly stay on land.

This guide describes the modest number of amphibians and reptiles including two venomous snakes that can be found in Los Alamos and the surrounding areas. An excellent reference for more information is Amphibians and Reptiles of Los Alamos County by Teralene S. Foxx, Timothy K. Haarmann, and David C Keller.

Reptile and Amphibian References

Amphibians and Reptiles of Los Alamos County [PDF]
Bartlett, R.D., Bartlett, P.P., 2013 New Mexico’s Reptiles and Amphibians: A Field Guide. University of NM Press
Biota Information System of New Mexico
Degenhardt, W.G., Painter, C.W., Price, A.H., 2005 Amphibians and Reptiles of New Mexico. University of NM Press
Encyclopedia of Life
New Mexico Herpetological Society
The Reptile Database

Subject Area Experts (all guides)

Steve Cary (butterflies)
Beth Cortright (insects)
Terry Foxx (invasive plants)
Leslie Hansen (mammals)
Richard Hansen (fish, mammals)
Dorothy Hoard (butterflies, trees)
Chick Keller (flowers, herbarium)
Shari Kelley (geology)
Kirt Kempter (geology)
Garth Tietjen (reptiles)
David Yeamans (birds)

Web Development and Content Management

Pat Bacha
Jennifer Macke
Graham Mark
Akkana Peck


Please contact us for local nature questions and sightings. We welcome comments, corrections, and additions to our guides.

For more information about local nature, please visit our Nature Blog or subscribe to PEEC This Week.

Make Selection

Common     Include rare


---- OR ----

Showing 4 of 39 reptiles and amphibians.

Photo: male by alikat


Photo: female by Sally King

Eastern Collared Lizard

(Crotaphytus collaris)

Family: Crotaphytidae (Leopard Lizards)
Size: 8 - 14 in (20 - 36 cm)

Status: native; uncommon
Habitat: arid areas with large rocks and hilly regions with limestone ledges
Typical location: Pajarito Plateau, White Rock Canyon

Large lizard with a dark stripe near the throat is most commonly found from late April to May. They like boulder-strewn or talus slopes where they bask and prey on insects and other lizards. They are mainly insectivorous. When startled they will run with forelegs lifted off the ground and the tail raised.

Tracks   Info    Photos   Distribution    

Photo: juvenile by Jennifer Macke


Photo: adult by Beth Cortright

Hernandez's Short-horned Lizard, Greater Short-horned Lizard, Mountain Short-horned Lizard

(Phrynosoma hernandesi hernandesi)

Family: Phrynosomatidae (North American Spiny Lizards)
Size: 2.5 - 5.9 in (6 - 15 cm)

Status: native; locally common
Habitat: open rocky or sandy plains; forested areas up to 9,000 ft (2,700 m)
Typical location: Deer Trap Mesa, White Rock, Kwage Mesa

This squat little lizard has an oval shaped body and dagger-like head spines. As this lizard scurries away in a waddling movement, it is hard to resist picking it up. Keeping this lizard in captivity generally results in its death because it eats hundreds of ants daily. These lizards are less common than they were in the past.

Tracks   Info    Photos   Distribution    Featured    
Ornate Tree Lizard

Photo: Jennifer Macke


Photo: male by Robbie Deans

Ornate Tree Lizard, Common Tree Lizard

(Urosaurus ornatus)

Family: Phrynosomatidae (North American Spiny Lizards)
Size: 4.5 - 6.3 in (11 - 16 cm)

Status: native; locally common
Habitat: rocks, fence posts, and buildings in arid regions
Typical location: Pajarito Plateau, White Rock Canyon

At first glance, the tree lizard may look similar to the more-ubiquitous Fence Lizard. Indeed, they are similar in overall size and shape. However, the tree lizard differs in color pattern and has a more flattened body shape. The coloration of this lizard varies from population to population, probably influenced by the color of the soil. Like the Fence Lizard, the male may have blue belly patches. Despite the name, the Tree Lizard is almost always seen on rocks, not trees.

Tracks   Info    Photos   Distribution    Featured    

Photo: juvenile by Jennifer Macke


Photo: adult by Jennifer Macke

Plateau Fence Lizard, Blue Belly Lizard

(Sceloporus tristichus)

Family: Phrynosomatidae (North American Spiny Lizards)
Size: 3.5 - 7.5 in (9 - 19 cm)

Status: native; common
Habitat: sunny locations with open woodlands or prairies
Typical location: Pajarito Plateau, White Rock Canyon

By far the most common lizard in the area. The main body color is gray, brown, or reddish with light stripes along either side of the back. Adults may appear to be solid gray-brown with little patterning. The underside of the males has bright blue belly patches. They can be found in a wide variety of environments. They eat insects. These quick moving lizards will lose their tail when grasped by a predator, but it will eventually grow back.

Tracks   Info    Photos   Distribution    Featured    
Scroll to Top