7 Types of Lizards Found in Illinois! (ID Guide)
“What kinds of lizards can you find in Illinois?”
I was amazed by the number of lizards in the United States – well over 150 species! Some species live only in a small area, and some are widespread over hundreds of miles.
Today, you’ll learn about 7 different kinds of lizards in Illinois.
#1. Six-Lined Racerunner
- Aspidoscelis sexlineata
- 2.25 to 3.75 inches long from snout to vent (length does not include the tail).
- “Dark fields,” or broad stripes in between lighter stripes on whiptails, are brown to black.
- 6-8 light stripes vary in color from white or yellow to gray-blue.
- In males, coloring is much brighter, with greens on the back and light turquoise on the belly.
The Six-Lined Racerunner has the widest range of all lizards in Illinois.
They thrive in varied habitats, including grassland, rocky terrain, wooded areas, and even floodplains. So, you have a good chance of seeing one as long as you’re within their range!
Six-Lined Racerunners are insectivores, and their primary food source is termites. However, they also eat beetles, ants, and spiders, so these small whiptails can be handy to have around if you have a pest problem.
The Six-Lined Racerunner lives up to its name, clocking speeds at up to 18 miles per hour! They have no problem outmaneuvering predators and curious humans!
#2. Eastern Fence Lizard
- Sceloporus undulatus
- 1.5 to 3.5 inches long from snout to vent (length does not include the tail).
- Coloration is highly varied – grayish-white, brown, reddish, and nearly black are all common.
- Females have dark, wavy lines across the back. Males have two patches of blue on the throat.
You’ll likely find the Eastern Fence Lizard in southern Illinois in open forests with plenty of fallen logs and debris to hide in. They’re most active during the early morning before it gets too hot.
Eastern Fence Lizard Range Map:Credit: Virginia Herpetological Society
Eastern Fence Lizards eat twice per day, and their diet is made up of insects like ants, beetles, and grasshoppers. They are foragers, which means they’ll leave their homes searching for food but often return to the same general area at night.
In Illinois, the Eastern Fence Lizard has adapted to a small but dangerous threat – imported fire ants!
Bites from fire ants can kill an Eastern Fence Lizard in less than an hour. To combat these non-native insects, these spiny lizards have adapted longer arms and legs, thicker skin, as well as new behaviors like climbing trees to stay out of harm’s way.
#3. Common Five-Lined Skink
- Plestiodon fasciatus
- Adults are up to 8.75 inches long.
- 5 stripes are most apparent in hatchlings and fade as the skinks grow.
- Males have orange-red coloring on the jaw during the breeding season.
- Hatchlings are black with light stripes. The black coloring often fades to gray, and the lighter stripes darken.
Look for Common Five-Lined Skinks in southern Illinois in wooded areas near rotting stumps, outcrops of rock, and sometimes piles of boards or sawdust. Its diet consists of spiders, beetles, crickets, and other insects.
Credit: Virginia Herpetological Society
Females attend to their eggs throughout the incubation period.
They spend almost all of their time defending and caring for the eggs until they hatch!
If you happen to come across a nest, you may notice the mother curled up on top of or around the eggs. She also rolls the eggs to maintain their humidity, moves them back to the nest if they become disturbed, and even eats eggs that aren’t viable!
#4. Broad-Headed Skink
- Plestiodon laticeps
- Adults are up to 12.75 inches long.
- Coloring in males is uniform brown or olive. Females often keep some form of stripes that are more apparent in hatchlings.
- The tail is gray in adults and blue in young.
- Males develop orange-red coloring on the jawline during the breeding season. Sometimes the entire head turns bright orange.
Look for Broad-Headed Skinks in southern Illinois in swamp forests, woodlands, or vacant lots with debris.
You can easily recognize this species by its triangular head!
Credit: Virginia Herpetological Society
Broad-Headed Skinks are one of the few skink species at home among trees! They will often climb trees for cover and protection from predators. They forage on the ground for their food, searching leaf litter and debris for insects and spiders.
#5. Little Brown Skink
- Scincella lateralis
- Adults are up to 5.75 inches long.
- Coloring is golden-brown to almost black with dark stripes that usually blend in with the main body color.
- The belly is white, sometimes with a yellowish cast.
In southern Illinois, they’re often called Ground Skinks because they live on the forest floor.
They can also be found in gardens and urban areas with lots of debris or litter to hide in.
Credit: Virginia Herpetological Society
Believe it or not, Little Brown Skinks have the interesting talent of seeing with their eyes closed! But honestly, it just looks like their eyes are closed. Technically, they have a window in their lower eyelids that allows them to see at all times.
That’s a very handy adaptation for one of the smallest reptiles in Illinois. The Little Brown Skink has many predators, including snakes, larger lizards, and birds of prey. When they try to sneak up on a “sleeping” Little Brown Skink, often the skink can run away using the element of surprise!
#6. Slender Glass Lizard
- Ophisaurus attenuatus
- 22 to 47 inches long.
- Coloring is generally brown to black, with whitish markings in the middle of the scales.
- Younger individuals have dark stripes along the back and sides, and older individuals develop faint crossbands.
Slender Glass Lizards live in dry grasslands and open forests in Illinois.
They eat insects, spiders, small rodents, and small lizards. However, unlike snakes, they do not have flexible jaws, which means they can only eat prey smaller than their head!
Credit: United States Geological Survey (USGS)
Glass lizards are named for their extremely fragile tails, which can break off even without being touched. Slender Glass Lizards are rarely found with their original tail intact because they break so often! If you notice that the end of its tail is tan with no stripes, you can be sure the lizard lost its original tail.
You’re likely to find a Slender Glass Lizard in animal burrows or piles of debris.
There are two subspecies:
- Western Slender Glass Lizards (O. attenuatus attenuatus) have shorter tails.
- Eastern Slender Glass Lizards (O. attenuatus longicaudus) have longer tails.
#7. Mediterranean House Gecko
- Hemidactylus turcicus
- 1.5 to 2.5 inches long.
- The pupils are vertical, and the eyes are large and round with immovable eyelids.
- This species has two color phases for camouflage.
- Pale phase: the coloring is light pink to pale yellow or white with brown or gray blotches.
- Dark phase: the coloring darkens to gray or brown, obscuring the blotches on the back.
You might be surprised to learn that there are ANY geckos in Illinois, and you’d be almost right – this species isn’t native! The Mediterranean House Gecko was introduced to Illinois via imported plants carrying their egg clutches. They’re adaptable to so many environments that their population quickly outpaced any of our native geckos!
Mediterranean House Geckos are nocturnal, but this won’t stop you from being able to find them. They’re considered an “urbanized” species, which means they’re just as happy to live inside your house as they are in the wild!
Virginia Herpetological Society
They eat insects attracted to lights and are commonly found on walls, ceilings, and window screens in homes. Outside, look for them in rock crevices or cracked tree trunks.
In addition to being comfortable around humans, Mediterranean House Geckos in Illinois are a vocal species. The mating call of males is a series of clicks, and they frequently make a squeaking noise if threatened.
Even though Mediterranean House Geckos aren’t native to Illinois, they’re so well-recognized that they belong on any list of geckos in our area.
Do you need additional help identifying lizards?
Try this field guide!
Which of these lizards have you seen in Illinois?
Leave a comment below!
Also, if you enjoy this article, make sure to check out these other guides!
14 FROGS Found in Illinois! (ID Guide)
16 Types of TURTLES in Illinois! (Both aquatic and land)
27 Kinds of SNAKES That Live in Illinois! (Includes venomous species)