Blue Belly Lizard

“The blue belly lizard has small microscopic pores on the legs that release pheromones into the air and attract mates.”

The blue belly lizard, also known as the western fence lizard, is among the most common reptiles in the western United States.

They are often seen bathing in the sunlight around outdoor trails or buildings and homes. The sparkling blue scales of the male lizard are a distinctive marker of this species.

These scales serve an important role in the reproductive process. This article will cover some interesting facts about the identification, habitat, and diet of the blue belly lizard in the wild, as well as how to care for them as pets.

Scientific Name

The scientific name of the blue belly lizard is Sceloporus occidentalis. The genus name Sceloporus is derived from two Greek words: Skelos, meaning leg, and porous, meaning pore or hole.

This is in reference to the large pores in the leg that release the pheromones. The species name occidentalis is simply the Latin word for the west.

The genus to which it belongs also includes other fence lizards and spiny lizards, all of which are common to the United States.

Appearance

The blue belly lizard can be identified by the tan or gray-colored scales with wavy stripes on the back and bright blue scales around the sides and bottom of the abdomen. Only the adult male has this bright blue coloration. The female and juveniles tend to have just duller gray scales.

One of the major identification markers for the entire genus is the presence of sharp, spiny scales; hence why the genus is called the spiny lizards. Most members of this species measure somewhere between 4.3 inches and 8.3 inches long from the tip of the head to the end of the tail.

They have long and sharp claws that enable them to easily climb trees. While they do look quite similar to the eastern fence lizard, their range doesn’t overlap at all, which should make identification easier.

Behavior

Like all other reptiles, the daily behavior of the blue belly lizard is oriented around the ambient outdoor temperature of the surrounding environment.

Because they can’t produce enough of their own body heat to survive, the blue-belly lizards need to spend much of their time absorbing sunlight.

They can be seen in the daylight hours sunning on rocks, stony paths, logs, and fence posts; they tend to prefer high places, but any location will work for them. Their scales frequently change colors from light to dark, but this is probably done for the purpose of regulating temperature (the amount of heat they absorb) rather than camouflage.

The blue-belly lizard tends to remain by itself for most of the year. The only time they come together is briefly in the mating season when the males maintain and defend their own territory. When winter arrives, they take shelter in crevices or holes and then enter a state of hibernation in which their activity and metabolism are massively reduced.

The length of time they hibernate depends on the surrounding temperature of their environment.

Evolution and Origins

Throughout their extensive evolutionary timeline, lizards developed specialized abilities to enable them to glide, swim, survive in arid environments, inhabit high forest canopies, traverse smooth surfaces, and even run across water.

These reptiles originated from a creature resembling modern-day lizards, known as the Lepidosauria, which was later succeeded by the emergence of the Sphenodontia, and while male tuataras do not possess reproductive organs, they evolved numerous characteristics that persisted and thrived in the Squamata order.

Additionally, a subspecies to the blue-belly lizard, the western fence lizard, also known as the blue-belly due to the blue coloration on its ventral abdomen, is a frequently found lizard species in the regions of Arizona, California, Idaho, Nevada, Oregon, Utah, Washington, Northern Mexico, and neighboring areas.

Different Types

Here are the different types of blue-bellied lizards:

• Great Basin fence lizard
• Northwestern fence lizard
• Sierra fence lizard
• Coast range fence lizard
• San Joaquin fence lizard
• Island fence lizard

Habitat

The blue belly lizard is found all over the westernmost part of the United States, including the states of Utah, Idaho, Nevada, Washington, Oregon, and Arizona. However, the greatest concentration occurs in the state of California. It is also found in small parts of northern Mexico.

This species is comfortable in all kinds of habitats, including grasslands, forests, farmlands, and shrublands. It tends to avoid the harshest deserts because it needs a nearby source of water to survive.

Six subspecies are generally recognized: the great basin fence lizard, the northwestern fence lizard, the Sierra fence lizard, the coast range fence lizard, the San Joaquin fence lizard, and the island fence lizard. This last subspecies is found only on the Channel Islands off the coast of California.

The other subspecies generally stick to the geographical range indicated by their names.

Predators and Threats

Apart from its natural predators, perhaps the greatest threat to the blue belly lizard in the wild is habitat loss. This species has been forced to adapt to the encroachment of humans throughout most of its range. Despite this, the species still remains very common.

What eats the blue-belly lizard?

This species is preyed upon by coyotes, snakes, bobcats, hawks, and numerous other birds and mammals. While the open spots in which they soak up sunlight do potentially expose the lizard to predators, they employ a number of defensive measures to get away.

If threatened, the lizard can completely detach the tail from its body. The tail will eventually grow again about three to five weeks later, but it may have a different length and color pattern than the old one. The lizard also has remarkably fast reflexes to evade potential predators.

It will often run into bushes or scurry up trees.

What does the blue-belly lizard eat?

This species preys upon numerous types of spiders, caterpillars, beetles, mosquitoes, and grasshoppers. It also sometimes consumes other small lizards. For a complete list of the foods blue belly lizards eat, check out our “What Do Blue Belly Lizards Eat?” page.

Reproduction and Life Cycle

The annual reproductive season of the blue belly lizard generally takes place between April and July. Lizards can locate each other in the wild by sensing pheromones.

The females also seem to prefer males with the brightest colorations and the longest tails. The males have the ability to tell other potential rivals to stay away from their mate by doing a kind pushup-like motion on logs or rocks to show off their brightly colored underside.

Once mating is completed, the female’s abdomen will visibly swell with her fully fertilized eggs. She will dig a hole in the ground and lay up to three clutches of 10 to 17 eggs at a time. After a gestation period lasting three to six weeks, the eggs will fully hatch and dispense their young.

The juveniles are quite small at first, measuring only about an inch long. They receive no supervision or care from their parent and must fend for themselves from the start. The juveniles become sexually mature in the spring of their second year. They have a typical lifespan of five to seven years in the wild.

Population

The blue-belly lizard is considered to be a species of least concern by the IUCN Red List. Population numbers appear to be stable, but few scientists have ever performed a good population estimate to determine how many currently live in the wild.