Week 10, Day 3: Lizards

This baby whiptail lizard is probably either a New Mexico whiptail or a plateau striped whiptail! (Photo by Beth Cortright)

Welcome to Take It Outside! This week, we are getting to know our local reptiles and amphibians, collectively known as herptiles — or herps!

In today’s post, explore some of the lizards that live here in Northern New Mexico.

Blog Post:

Anthony Sena, Emeritus Professor at Northern New Mexico College, looked at some of the lizards you might find in Northern New Mexico and their unique features. In particular, he wrote about our state reptile, the New Mexico whiptail lizard. Read his blog post here.

Dr. Sena will be the next Featured Naturalist at Los Alamos Nature Center. Look for his exhibit shortly after the nature center reopens.


Lizards are experts in camouflage. Check out the many different shapes and colors of lizards here.

Then, color your own camouflaging lizard! Cut out a lizard shape, color it, and then place it outside in a spot to camouflage. Play a game of hide and seek with your craft! Can anyone in your family find the lizard?


Outdoor Challenge (Beginner):

Flash is one of the fence lizards that lives at the Los Alamos Nature Center. (Photo by Jennifer Macke)

Go on a lizard behavior scavenger hunt! Can you find a lizard …

  • Sunning itself on a rock?
  • Cooling off in the shade?
  • Doing head bobs or push-ups?
  • Trying to catch an insect to snack on?
  • Crawling up a wall or big rock?
  • Chasing another lizard?

Let us know what you observe!


Outdoor Challenge (Advanced):

We have quite a few species of lizards on the Pajarito Plateau. Go outside and see how many different kinds of lizards you can find today. Depending on where you’re looking, you may be more likely to see some species than others. The species are listed below roughly according to how common they are, with the fence lizard being by far the most common species in Northern New Mexico.


Want to Learn More?

  • If you missed our last lizard-themed blog post by PEEC volunteer and biologist Jennifer Macke, check it out here to learn more about the lizard species you might find in Northern New Mexico.
  • In last week’s Critter Chronicles video, we featured Hazel, the Chihuahuan Spotted Whiptail Lizard, at the nature center. If you missed the livestream, you can watch that video here.
  • Be sure to check out PEEC’s online Reptiles and Amphibians Nature Guide to help you identify lizard species you find!
  • Explore how some lizards — like the New Mexico whiptail — are able to reproduce asexually in this Scientific American article.

Share Your Experience:

Tell us what you learn about our local reptiles and amphibians this week! We’d love to see your photos, too. Please send them to takeitoutside@peecnature.org or share them on Facebook or Instagram with the hashtag #peectakeitoutside.

Tomorrow, we’ll learn about snakes!

Lizard Tales

A New Mexico whiptail lizard photographed in eastern New Mexico. This is probably an adult lizard. Juveniles commonly have blue-green tails! (Photo by Jerry Oldenettel)

By Anthony Sena, Emeritus Professor, Northern New Mexico College

I have noticed quite a few fence lizards, Sceloporus undulatus, in and around a small arroyo that runs through my yard and on the walls of our home. This is the most common lizard seen around homes and gardens in Northern New Mexico. Female fence lizards lay two clutches of eggs during the spring and summer seasons, so they and the males must spend significant time outside of their burrows during the day. Like most lizards they are wary and quick, but if a person is non-threatening or temporarily motionless they eventually relax and scurry about looking for food, mating partners, and, if they happen to be males, potential competitors.

When males encounter other males they perform an instinctive behavioral ritual of front limb push-ups and rapid head bobbing, which is interesting and amusing. It is also fun to watch them thermoregulate as they move from basking in open sunlight to plant covered shaded areas or to see them touch their snouts to water drops on freshly watered plants.

A fence lizard climbing on a wall in the author’s yard. (Photo by Anthony Sena)

They do not actively drink, preferring to let moisture creep along their scales into their mouth. It seems like we have been having a higher percentage of high winds this spring, which, in general, reduces sightings of lizards. Lizards are bothered by wind and one reason for this may be that it generally makes finding insects much more difficult. (I also dislike spring winds because of juniper pollen!)

The New Mexico whiptail lizard, Aspidoscelis neomexicanus, is the New Mexico state reptile. Its distribution in the state closely follows the Rio Grande from Española south into Texas, with a few sparse and localized populations far removed from the river in several southwest counties of New Mexico. In Northern New Mexico, the lizard prefers areas of low shrubs and grasslands in perpetually disturbed sandy habitat along the river.

The New Mexico whiptail is an all-female parthenogenetic species that was produced by an original mating of two related but distinct whiptail species. Because of this, New Mexico whiptails have one-half of all their chromosomes derived from one type of parent lizard and one-half from another species. In most cases, hybridizations of this type between vertebrate species result in sterility of the offspring, but sometimes surprising outcomes like parthenogenesis, or “virgin-birth,” occur, where all subsequent generations of offspring produced by the hybrid are genetically identical to the mother. 

Distribution of the New Mexico whiptail lizard (Aspidoscelis neomexicanus) in New Mexico. (Image by William G. Degenhardt, et al., from Amphibians & Reptiles of New Mexico)

In a couple of remarkable studies published in 1975, Dr. Orlando Cuellar from the University of Utah provided evidence that populations of New Mexico whiptails were over 99% identical from Rio Arriba to Socorro County. More recent and current studies continue to show very little genetic variability within populations of this species. Some parthenogenetic species have shown a fascinating pseudo-mating ritual where females alternate male-like behaviors at given times in the “mating” season. This behavior is providing interesting details on brain hormones and reproductive development, even in all-female parthenospecies like the New Mexico whiptail.

A similar species, the little striped whiptail, Aspidoscelis inornatus, that may be confused with the New Mexico whiptail, is more commonly seen in the Española Valley in areas further removed from the Rio Grande, but the little striped whiptail lacks the distinctive wavy line found on the mid-back of the New Mexican whiptail lizard. An interesting note is that the little striped whiptail is the known (by matching chromosomal size and banding characteristics) parental species of the New Mexico whiptail!

In my immediate vicinity, there are few areas that provide easy access to the riverbank (most are private or Pueblo land), and unfortunately I have not observed any New Mexico whiptails this spring.

If you observe a New Mexico whiptail or another lizard, we’d love to hear about it! Send your photo or story to takeitoutside@peecnature.org.

Lizards Basking in Spring

A juvenile fence lizard basks on some gravel. (Photo by Jennifer Macke)

By Jennifer Macke

One of the hallmarks of springtime is the emergence of reptiles from their winter inactivity. Lizards and snakes spend the winter underground, burying themselves below the frost line. As the weather gets warmer, you will begin to see them out and about, at first just during the warmest part of the day. You may see them basking to warm up in the morning, and actively hunting prey in the early afternoon. If the evenings are still cold, they will retreat back underground at night.

First to Emerge

Since emergence depends on temperature, the first places you are likely to see lizards are in warm, sun-soaked sites. Look for them in the Rio Grande valley, and on warm mesa-tops. They emerge later in the mountains.

Emergence varies by species. The first species of lizard you are likely to see are fence lizards. This species is highly adaptable to a wide range of temperatures, and are quite tolerant of cool-but-sunny spring days. Some other species, such as the whiptails, require a higher temperature. Whiptails will emerge later, and have shorter periods of activity only in the warmest part of spring days.

Soaking in the Sun

Hazel, one of the critters at the nature center, is a Chihuahuan spotted whiptail lizard. (Photo by Jennifer Macke)

Basking in the sun serves two essential purposes for lizards: heat and vitamin D. Reptiles produce very little of their own body heat, and are almost entirely dependent on heat from their environment. Unlike us, they have a range of body temperatures in which they can function. Most reptiles can only digest food above a certain temperature, so they bask in order to be warm enough to digest their food.

Vitamin D is an essential nutrient for all vertebrate species, and sunshine is the major source for most lizards. Their diet of insects doesn’t provide enough vitamin D, so they depend on basking to provide it. In fact, scientific studies have shown that lizards bask longer when their bodies are deficient in vitamin D.

Pro Tip: Vitamin D is essential for calcium absorption, and thus helps build strong bones, both in humans and lizards.

Be an Instant Expert

To be a bird expert, you will need to learn more than 100 species, but being a lizard expert is easy. We have only about a dozen species in the area, and there are just two types that vastly predominate: the fence lizard and a group of related species that we will lump together as the whiptails. If you learn to tell the difference between the fence lizard and the whiptails, you can easily identify 90% of the lizards you see, and everyone will think you’re a pro!

Pro Tip: You can distinguish between the fence lizard and the whiptails on the basis of their tail length.

Let’s take a closer look at the differences between fence lizards and whiptails.

Eastern fence lizards are the first lizards to emerge in the spring. (Photo by Jennifer Macke)

Eastern Fence Lizard (Sceloporus undulatus)

Fence lizards have blue patches on their chin and belly, giving them the common name “Blue-belly.” (Photo by Jennifer Macke)

The first lizards to emerge in spring are also the most common: the fence lizard. This lizard goes by several different common names, including Swift, Prairie Lizard, and Blue-belly. Some individuals, especially juveniles, have a herringbone-like pattern of dark brown markings on a light brown body. Some adults also have this pattern, or their markings may fade to a uniform gray-brown.

Fence lizards have blue patches on their chin and belly, giving them the common name Blue-belly. These patches are larger and more obvious in males than in females. In spring, you may see a male Fence lizard doing “push-ups” in order to display his blue belly to a nearby female.

The Whiptail Lizard Family (Aspidoscelis spp.)

A plateau striped whiptail lizard, one of five whiptail species that occur in our area. (Photo by Selvi Viswanathan)

The whiptails are a group of related species named for their long, thin tails. We have five whiptail species that occur in our area, but even experts have difficulty distinguishing some of the species at a glance. The whiptails require very warm temperatures to be active, and thus their emergence comes later in spring.

Whiptails are very fast-moving. They often display jerky start-stop movements, which can create a unique sound when they move through leaf litter or dry grass.

Most whiptails have “racing stripes” running the length of their body. Like fence lizards, the whiptails have courtship rituals in springtime, so spend some time watching their antics.

Pro Tip: Listen for lizards moving under bushes.

Other Lizard Species

A horned lizard in the Jemez Mountains. (Photo by Beth Cortright)

Some of the less-common lizards in the local area include the tree lizard, the horned lizard (also known as horny toads), the many-lined skink, and the collared lizard. For additional information and photos, check out PEEC’s online Reptile Guide.

Now that you are an instant expert, see if you can observe some basking lizards and watch their interesting behaviors this spring!