The Great Plains skink is a robust ground-dwelling lizard, the largest skink species in the United States. It has a light tan to gray ground color, with the scales on the back, sides, legs, and tail edged in brown or black, making it look speckled. These dark markings may combine to form irregular lengthwise stripes along the back, sides, and tail. Along the sides of the head and just above the belly, there may be a wash of yellow and a few faint orange spots. The belly is plain light gray. The scales along the sides are in oblique (slanted) rows, and this is Missouri's only lizard species with such a scale pattern.
The hatchlings are black with bluish tails and a series of white or orange spots on the anterior (forward) sides of the body and onto the head. (Note that the juveniles of some other skink species also have black bodies with blue tails.)
Adult total length: 6½ to 13¾ inches.
Great Plains skinks have been found in Missouri's a few counties along the western edge of the state. Our state and northwestern Arkansas represent the easternmost extent of the overall range.
Habitat and Conservation
A rare species in Missouri, as our westernmost counties represent part of the easternmost extent of their overall range. The ideal natural habitat for this species is native prairie with low hills, sparse vegetation, and numerous rocks embedded in the soil. Most behavior and life history information is from observations in Kansas and other states to our west. In Missouri, Great Plains skinks have been found beneath rocks, on rocky roadcuts, and around buildings with landscaping rocks. They may also occur on the western slopes of loess mounds in northwestern Missouri.
They overwinter below the frost line in burrows, under rocks, or deep within rock crevices.
In Missouri, this species is active from March into October, peaking from April to early July. Great Plains skinks are excellent burrowers. They spend a great deal of time in burrows under rocks, burrows in loose soil, or within rocky crevices. In these locations, they are safe from a variety of predators, can find insect prey, and can be warmed by sun-heated shelter rocks. During the day, when the air temperature is over 70 degrees, they venture into grassy openings to search for prey.
Great Plains skinks move quickly to escape predators. They will readily detach their tails to distract a predator if needed. If captured, they will bite to defend themselves.
The Great Plains skink eats a variety of insects, including crickets, grasshoppers, and beetles, as well as spiders and land snails; young individuals have been observed eating smaller snails. Great Plains skinks occasionally eat the young of other lizards.
A Missouri species of conservation concern due to few records and lack of appropriate rocky habitat throughout the grassland areas of the state.
The Great Plains skink is a peripheral species in Missouri and may never have been common. There continue to be a few scattered sightings for this species in western Missouri. Reports in Kansas show this reptile is quite common and occurs in numerous counties that border Missouri.
As with most rare species, protecting the habitat it needs is a key to its continued presence in our state.
Courtship and breeding apparently take place in May. Females might not breed every year. Eggs are usually laid in a burrow excavated by the female under a large flat rock in June or July, with 5–32 eggs per clutch. Larger females produce more eggs per clutch. The female remains with her clutch, guarding it for one to two months, until the eggs hatch.
Individuals become sexually mature at about 3 years of age. In captivity, they may live 8 years or more.
Missourians have a unique, diverse combination of natural landscapes, including Ozark hills, Bootheel swamps, big river habitats, and our northern and western prairies. The Great Plains skink is a valuable component of our beautiful and historically significant prairies. Prairie conservation helps not only this species but also many other native plants and animals. Today, there are very few prairies left, but before European settlement, more than a third of the state was covered with them.
People may wonder why anybody should be concerned with plants and animals whose overall range lies in adjacent states. There are many reasons why Missourians should take care to maintain species that occur peripherally in our state. First, they are part of our state's natural heritage, so the responsibility of conservation lies with us. Second, animals and plants that live on an edge of their overall range often turn out to have different genetic lineages and characteristics that make them valuable to their species' overall diversity. For example, perhaps they have genetic traits that make them capable of surviving a disease or certain extreme environmental conditions that the rest of their population lacks. This is increasingly important as climate patterns shift, and species' ranges may need to change in response. Also, sometimes a peripheral population turns out to be a unique subspecies, or even a different species, once it is studied more thoroughly.
Like most lizards, this species preys on insects and other small animals and naturally keeps their populations in check. It, and its more vulnerable eggs and juveniles, is preyed upon by larger predators, including hawks, shrikes, and mammals such as badgers and skunks.
The skinks (Scincidae) are a large family of lizards with species on nearly every continent and many oceanic islands. There are over 1,580 species worldwide, representing about 115 genera. The smallest species may be only 3 inches long; the largest (in Australia) may reach a length of over 2 feet. Most species have smooth, overlapping scales and live either on or under the ground. Five genera with about 15 species occur in the United States. A few nonnative species have been introduced into southern Florida. Missouri skinks are represented by two genera with a total of six species and one additional subspecies. All our skinks can quickly break off their tails if grasped by a predator.