Missouri is home to 11 species of lizards, all of which are harmless to humans. In general, lizards have a small head, short neck, and long body and tail. Like all reptiles, they are ectothermic, or cold-blooded. They are members of the order Squamata, or scaled reptiles, along with snakes and amphisbaenians. Lizards are closely related to snakes, but are usually easily identified by their legs (snakes are legless); however, there are legless lizards. These can be recognized by movable eyelids and external ear openings (“Lizard Facts”).
Missouri Lizards live in three different types of environments– forests, glades, and prairies. Each lizard has formed its own, unique adaptations to deal with its surroundings. A forest is a piece of land with many trees on it, and Missouri’s forests are mostly a mix of oaks, cedars and pines. The state currently has 15.3 million acres of forest land (“Forests and Woodlands”). Glades are rocky exposures on hillsides, and they have thin soil making it hard for trees to grow in the area (“Glades”). Prairies are large open areas of grassland. Missouri’s prairies are considered tallgrass prairies because the soil is able to support taller plant life compared to the Great Plains of North America. Some species of grass get above six feet (“Prairies”)!
Lizard eggs in Missouri are leathery-shelled and porous; they can expand by the absorption of moisture as the embryos grow. The group of eggs produced at a single time from a lizard is called a clutch. Most Missouri Lizards will lay them in loose soil, under a rock, or in a rotten log and leave them, except for skinks and glass lizards. They actually wait and protect the eggs until they hatch (“Lizard Facts”).
Family: There are five different families of lizards in Missouri
Family: Crotaphytidae (collared lizards)
Eggs: lays 2-21 once a year
Length: 8-14 inches
The eastern collared lizard is a medium-sized, colorful lizard with a large head and powerful jaws perfect for capturing grasshoppers, beetles, spiders and sometimes other lizards. Its name comes from the two black lines, or “collars,” around its neck. The males are typically more colorful with a blue-green tint and bright yellow spots while the females are often duller with yellow-brown tints and faint light colored spots. Females will often have red bars or spots on the side of their necks if they are currently heavy with eggs. People will often see this species basking on rocks from April to September with some juveniles staying active through October. They can be found in the southern half of the state, and mating occurs between May and June. They are often preyed upon by snakes, hawks and roadrunners (“Eastern Collared Lizard”).
The eastern collared lizard is unfortunately a Species of Conservation Concern, but not too long ago the lizard’s population was much lower because of decades of fire suppression. This act caused Eastern Red Cedar (one of the only native trees capable of growing in the glades) to overtake the lizards’ natural environment making it almost impossible for these highly adapted species to survive. Luckily faculty and students at Washington University in St. Louis and Missouri’s Department of Conservation created effective plans on how to restore the glades and reintroduce the species. Now the population is beginning to thrive again. The restoration of Missouri glades did not only help the collared lizards but also several other plant and animal species unique to the glades (Lutz).
Eastern collared lizards have been the subject of several studies for sexual selection. They found out that two males will fight to the death for a female unless the males live near each other. These lizards seem to recognize their neighbors and are much less aggressive around them. This idea is known as “dear enemy” phenomenon (Vitt).
Fun fact: Historically, collared lizards are nicknamed “mountain boomers” because it was blamed by settlers to cause loud noises heard in valleys. The collared lizard is actually completely voiceless (“Collared Lizard”).
Eggs: lays around 20 eggs once a year
Length: 2-4 inches
The Texas horned lizard is a stocky, flat-bodied lizard that almost looks circular in shape. It has a short tail, and it is named after the enlarged scales around its head and down its body that resemble horns. It is typically a light yellowish brown to brownish red or tan base color with dark markings on the body. It mostly dines on ants while it is eaten by coyotes, foxes and predatory birds (Smith 290-291). They are often seen on the edge of gravel or dirt roads basking in the sun from April to September (“Texas Horned Lizard”). The Texas horned lizard’s main defense is its camouflage, but if put in a difficult situation, it will first try to suck in air to look inedible (too big for the animal to eat). If that does not work, they will then squirt blood from their eyes. Specialized muscles allow the lizard to fill its eyelid with blood and shoot it up to six feet away. This process is known as auto-hemorrhaging (DuHamel).
Unfortunately the Texas horned lizard is a Species of Conservation Concern in Missouri. It was common in several southwestern counties, but now it is only distributed in some counties in the Southwestern corner of Missouri (“Texas Horned Lizard”).
Research on Texas horned lizards has mostly been focused on how to save this species from local extinctions, but it is helping scientists understand the effects pesticides can have on a food chain. Since Texas horned lizards eat almost solely ants, it is easy to severely hurt the population. The hypothesis is pesticides are killing the local ant populations which is then killing the local lizard population (Lamme).
Fun fact: The Texas horned lizard is also known as the “horny toad” because of its roundish, toad-like appearance.
Eggs: lays 2 clutches of 4–17 eggs per year
Length: 5 inches
The prairie lizard is a small reptile with its tail being over half its body length. It is typically gray or brown, and it has a wide, gray dorsal stripe. Males can easily be identified by having two bright blue patches on their underside and throat. During mating season, males will bob their head to show off this gorgeous color to females. Since males are territorial, they might also show off their undersides, and do push-ups, to scare off other lizards. A person could expect to find this lizard on the edge of the woods or a field on sunny days in late March through early October. It eats a wide variety of insects and spiders including ants, beetles and grasshoppers and is preyed upon by many mammals and birds (“Prairie Lizard” [MDC Discover Nature]). Like skinks, it is capable of dropping its tail and regenerate it if threatened.
The prairie lizard is common in Missouri with no conservation concern. It is currently found in the southern half and northeast corner of the state (“Prairie Lizard” [MDC Discover Nature]).
Fun Fact: The families Phrynosomatidae (including Texas horned lizard and prairie lizard) and Crotaphytidae (including eastern collared lizard) were considered subfamilies to the giant family Iguanidae until Frost and Eleridge questioned their placements in 1989 (Heying). The prairie lizard went through even more reclassification. Until 2002, this lizard was classified as a subspecies of Sceloporus undulatus (eastern fence lizard). Leaché and Reeder were the first to say that the prairie lizard is its own species (“Prairie Lizard” [MDC Discover Nature]; “Prairie Lizard” [COPARC]).
Eggs: lays 5-16 eggs once a year
Length: 26 inches
The slender glass lizard is the only legless lizard in Missouri, and it is the longest lizard in the state. The tail is about two-thirds of its body length, but it can break off very easily if threatened. It is typically a tan or cream color with black stripes going down the body. Older specimens sometimes lose some of their stripes. People might see these lizards during the day in April through October basking on the side of a road. They eat insects, small animals and even bird eggs and are preyed upon by snakes, mammals and birds (“Western Slender Glass Lizard”).
The slender glass lizard is considered a species of least concern by the International Union for Conservation of Nature, or IUCN. Presumably, the slender glass lizard is found all throughout the state (“Western Slender Glass Lizard”).
Fun Fact: Another way they are different from snakes is they do not slither. Instead of using specialized abdominal or neck muscles, they push off of objects. They can actually get stuck in the middle of roads because there is nothing to push off of for movement (Eastern Slender Glass Lizard).
Eggs: lays 1-6 eggs once a year
Length: 8 inches
The six-lined racerunner is an exceptionally fast lizard. Its base color is dark brown with six stripes that are typically yellow but can be pale blue, gray or white, and they stretch from the lizard’s head to its tail. Its head can have a green or blue tint, and the males can be identified by having a bluish gray belly while females have a pink or white belly. With a gray-to-brown tail that is over 50% of its body length, they will sacrifice their tails when grasped by a predator. It can also escape by running into a creek. It is typically active during the day from May through mid-September, and it is often found under rocks or shallow burrows in loose soil. It consumes insects, spiders, and scorpions while it is preyed upon by snakes, birds, mammals and lizards, especially collared lizards (“Six-lined Racerunner”).
There are actually two subspecies of the racerunner found in Missouri: the eastern six-lined racerunner (Aspidoscelis sexlineata sexlineata) and the prairie racerunner (A. sexlineata viridis). The eastern six-lined racerunner was described above, and it is very common in eastern and southeastern sections of the state. The prairie racerunner has seven stripes and a wash of green over the front half of the body. It lives statewide except northern and north-central counties in Missouri (“Six-lined Racerunner”).
The population of six-lined racerunners is considered stable in Missouri and is not a species of conservation concern. This includes both subspecies found in the state (Bonavita).
There seems to be a social ranking in six-lined racerunner populations. In Oklahoma, studies were performed showing aggressive chasing and biting by big, usually male specimen. Even a submissive posture was recorded for subordinate individuals (Carpenter).
Fun Fact: The six-lined racerunner can go up to 18 mph while sprinting and was named by Carolus Linnaeus in 1766 (“Eastern Six-lined Racerunner”).
Family: Scincidae (skinks)
Eggs: lays 7-11 eggs once a year
Length: 5 to 6 inches
The coal skink is a medium-sized, shiny lizard with smooth scales and short legs. It is usually tan or brown and has a dark brown or black stripe bordered with thin, white stripes down the sides of its body. Males have dark orange coloring on the side of its head during breeding season. It is active on sunny days from late March to mid-September in damp woods; however, it is rarely seen because of its shy temperament. Since it is uncommon to see one, not much is understood about their behavior. It eats a variety of insects and spiders and is preyed upon by snakes, mammals and birds. Like all skinks of Missouri, it is capable of breaking off its tail and regenerate it if grasped by predators (“Southern Coal Skink”).
It is uncommon to see a coal skink; therefore, more research needs to be conducted to determine its status. It can be found throughout the southern half of the state (“Southern Coal Skink”).
Fun Fact: Skinks are the most well-known family of reptiles to shed their tails and regrow new ones. This process is called autonomy, and scientists are studying the cellular actions of this regeneration to maybe one day help humans with spinal cord injuries (“Southern Coal Skink”).
Eggs: Information in description
Length: 10½ inches
The broad-headed skink is a wide-headed, large lizard. It is an olive-brown color, and females usually have stripes going down their bodies. Males are easily identified by their swollen jowls and orange heads. Juveniles have stripes similar to females but also have bright blue tails. Juvenile’s dramatic color variation is likely caused to protect them from adult skinks. Males will attack others if they look like adult skinks. They are active during the day from April to October, and these reptiles are more likely to be seen in large dead trees. Scientists believe broad-headed skinks participate in communal nests. With most nests containing more than 10 eggs, it is very likely that more than one female laid her clutch in the nest. They eat insects and are preyed on by mammals and birds (“Broad-headed Skink” [MDC Discover Nature]).
Populations of broad-headed skinks are considered stable in the state, and they are not a species of conservation concern (Quesenberry). They inhabit the southern two-thirds of Missouri (“Broad-headed Skink” [MDC Discover Nature]).
Fun Fact: The Latin word latus means “broad” and the Latin suffix –ceps means head. This translation is why the species’ name is laticeps (“Broad-headed Skink” [Chesapeake Bay Program])
Eggs: lays 4-14 eggs once a year
Length: 6½ inches
The five-lined skink is a moderately large, common lizard. It has a streamlined body and short legs. Males are typically tan with a few light stripes and a dark stripe going down its body, and they have bright orange heads similar to the broad-headed skink. Females are brown with a dark stripe and five, very-defined, tan stripes. They also keep a bluish tint to their tails. Juveniles are black with five yellow stripes and a blue tail (Smith 347-349). It is likely to find one of these lizards in open woods from April to October on sunny days. They consume a variety of insects and spiders and are preyed upon by snakes, larger lizards, birds and mammals (“Five-lined Skink”).
The five-lined skink is common in Missouri with no conservation concern, and it is actually the most common lizard found in the state. It is currently found statewide except for the far northern counties (“Five-lined Skink”).
Five-lined skinks’ dominant and submissive behaviors have been studied. The submissive specimen tended to avoid the bigger, more dominant lizards, and tail wagging may be a sign of submission. If the submissive and dominant lizards were a body length away, 76% of the time one lizard would lunge toward the other (Paulissen).
Fun Fact: The five-lined skink and the broad-headed skink are very similar in appearance. The best way to tell which is which is looking at the post-labial scales which are found one on top of the other in the space between the lip scales and the ear hole. The five-lined skink has two of these scales while the broad-headed skink will have one or none (“Five-lined Skink”).
Eggs: lays about 11 eggs per clutch (may not be every year)
Length: 11 inches
The great plains skink is a large, beautiful lizard that has a very interesting pattern. It has a base color of tan or gray, but each scale’s back edge has a dark crescent mark forming a net-like pattern. The limbs and tail can be tinted with orange, and the back is often tinted with pink. Juveniles are typically jet black with white or yellow spots on the head and a bright blue tail (Brennan). It is rare to see in Missouri, but it might be spotted on hot days in March to early October. If picked up, it will inflict a painful bite to defend itself. Not much is known about mating in the state for this species. It is probably during May, and not every female and male mate every year. It eats mostly grasshoppers, crickets and beetles and is preyed upon by snakes, mammals and birds (“Great Plains Skink”).
Unfortunately, the great plains lizard is a Species of Conservation Concern. It is rarely seen in Missouri, but it does inhabit the far western counties (“Great Plains Skink”).
Fun Fact: All Plestiodons (great plains, coal, broad-headed, five-lined, and prairie skinks) were classified under one giant genus called Eumeces. It was not until Brandley et al in 2005 determined that there are three distinct clades within the old genus (Rorabaugh).
Eggs: lays 5-18 once a year
Length: 5 to 7½ inches
The prairie skink is a long-tailed, thinly-built lizard. This species is the longest tailed skink in the state. It has a base color of tan or brown with a light mid-dorsal stripe and one or two dark lateral stripes which are edged with white. Sometimes as individuals age, their stripes fade, and during the breeding season, males will develop a reddish tint to their cheeks (“Southern Prairie Skink”). This skink spends a lot of time hiding under rocks but will become active for short periods during the morning or early afternoon. It eats a variety of insects and spiders and is preyed upon by snakes, birds and mammals (“Northern Prairie Skink”).
There are actually two subspecies found in Missouri: the northern prairie skink (Plestiodon septentrionalis septentrionalis) and the southern prairie skink (Plestiodon septentrionalis obtusirostris). The northern prairie skink is slightly larger and has more dark striping. It is also only found in one county in the northwest corner of the state. The southern prairie skink is slightly smaller and has fewer and fainter stripes. It can be found in certain southern counties in the state (“Northern Prairie Skink”).
With prairies across the country being destroyed, many populations of species that rely on this certain type of environment are being wiped out as well. Both subspecies of the prairie skink are unfortunately a Species of Conservation Concern (“Northern Prairie Skink”).
Fun Fact: The southern prairie skink was just recently found in southwest Missouri. Because of this recent discovery, not much is known on which counties have this subspecies (“Northern Prairie Skink”).
Eggs: lays 2-7 twice a year
Length: 4 inches
The little brown skink, or ground skink, is a small, slender lizard that almost never climbs (unlike all other forest-dwelling, Missouri lizards). It is typically brown but can be golden brown or black with dark brown or black stripes going down the body (“Ground Skink”). It can also have black speckling around the stripes. Ground skinks are most active on sunny days in April through to October, but it is very rare to see this species in the open. It likes to stay hidden under leaf litter on the forest floor. It eats insects, spiders and earthworms, but it is preyed on by snakes, larger lizards, mammals and birds. These skinks are so small even bluebirds have been spotted feeding little brown skinks to their hatchlings (“Little Brown Skink” [MDC Discover Nature]).
Little brown skinks are classified as common in the state of Missouri and can be found in most of the state except for the northwest corner (“Little Brown Skink” [MDC Discover Nature]).
Tail autonomy has been properly researched for little brown skinks. Dial and Fitzpatrick in 1983 testing whether or not the tail would actually distract the predators and allow for the lizard to escape. Using a cat and a snake, the tail strategy had overwhelming success; the skink escaped most of the time. The little brown skink had a better escape percentage compared to other lizard because the broken-off tail thrashes more in this species (“Little Brown Skink” [iNaturalist]).
Fun Fact: The little brown skink is not only the smallest lizard in Missouri, it is the only lizard in the state to have a clear scale on its lower eyelids. This adaptation allows the skink to see even when its eyes are closed (“Little Brown Skink” [MDC Discover Nature]).
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This page was produced by Logan Lacy in 2019
All photos used on this page, except the eastern collared lizard, are from https://www.flickr.com/