Lizards are reptiles. Most have four legs, are covered in scales, and have a skull composed of quadrate bones. Lizards possess external ears and most have movable eyelids.
Lizards are comprised of 40 different families, resulting in a tremendous variety in color, appearance and size. Due to their smooth, shiny appearance, some lizards can appear slimy or slippery although their skin is actually very dry due to a lack of pores to excrete water and oils.
Most lizards produce eggs that hatch outside the body, though a few species give birth to live young.
Many lizards are capable of regeneration of lost tails.
Many lizards are good climbers or fast sprinters. Some can run on two legs, such as the Collared Lizard and the world's fastest lizard, the Spiny-Tailed Iguana.
Many lizards change color in response to their surroundings or in times of stress. The most familiar example is the chameleon, but more subtle color changes occur in other lizard species as well, such as the Anole, also known as the "American Chameleon," and "House Chameleon" or "Chamele".
All lizards are capable of swimming, and a few are quite comfortable in aquatic environments.
Lizards feed on a wide variety of foods including fruits and vegetation, insects, small tetra pods, carrion and even (in the cases of large predator lizards) large prey such as deer and other big animals.
Only two lizard species are venomous: the Mexican Beaded Lizard and the Gila Monster, both of which live in Northern Mexico and the Southwest United States. Even though myths and legends surround these creatures because their bite can cause serious injury, no human fatalities have ever been recorded.
Most lizard species are harmless to humans. Only the very largest lizard species pose any threat of death; the Komodo dragon, for example, has been known to stalk, attack, and kill humans.
The chief impact of lizards on humans is positive, as they are the main predators of pest species; humans keep many lizards as pets; and still some are eaten as food.
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Varanus komodoensis
Komodo Dragons were first described by Western scientists in 1912. These huge lizards are found on the Indonesian islands of Komodo, Flores, Padar, and Rinca. It is believed they arrived at the smaller islands of Padar and Rinca by swimming as they are strong swimmers. The government has long been very protective of their dragons and has let only small numbers of them leave the country over the years. It takes a Presidential decree to get them out of Indonesia.
LEARN MORE ABOUT OUR KOMODO DRAGON!
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Here is some information on the lizards found in South Dakota. Two other species are recognized in the state but are found in such a limited range that there is some question as to whether they should be considered residents.
• Lesser Earless Lizard Holbrookia Maculata
Family: Phrynosomatidae, Earless and Horned Lizards
Description: 4-6 1/4" (10-16 cm). Small; with smooth granular back scales, 2 folds across throat, no external ears. Gray to brownish, depending on earth color. Usually has lengthwise rows of dark blotches separated by pale stripe down center of back and dorsolateral light stripes. No spots under tail. Male has pair of blue-bordered black marks on each side of belly behind foreleg. Female has orange throat during breeding season.
Subspecies:
- Northern Earless Lizard (H. m. maculata), small , dark blotches on back distinct, no blue in area of diagonal belly marks, blue in throat of males duller than in others; s. South Dakota to Texas panhandle, west into e. New Mexico, Colorado, and extreme se. Wyoming.
- Eastern Earless Lizard (H. m. perspicua), males with well-defined pattern of dark blotches on light background color and absence of white speckling; females difficult to identify; ec. Kansas south through to c. Texas.
- Speckled Earless Lizard (H. m. approximans), larger than H. m. maculata; males have numerous small light spots on upper surface; throat mottled; c. Arizona through New Mexico to extreme w. Texas, south into Mexico.
- Western Earless Lizard (H. m. thermophila), quite large, to 6 1/4" (16 cm), but otherwise similar to H. m. maculata; s. Arizona below 5,000' (1,500 m) and south into Mexico.
- Bleached Earless Lizard (H. m. ruthveni), light coloration, no dorsal blotches; restricted to White Sands region (Otero County), near Almagordo, New Mexico.
- Huachuca Earless Lizard (H. m. pulchra), larger than H. m. maculata, tail longer than body, no dorsal stripes; Huachuca Mountains and adjacent mountains of extreme southeastern Arizona, above 5,000 ft.
Breeding: Mates during spring and summer. Lays an average of 5-7 eggs, April to September; hatchlings appear May to October._
Habitat Sandy soil areas in grassy prairie, cultivated fields, dry streambeds, desert grasslands.
Range: S. South Dakota through the Great Plains to c. Texas, west through most of New Mexico and Arizona into Mexico.
Discussion Diurnal. Loss of the external ear may be an adaptation to this lizard's habit of burrowing headfirst into sand. It subsists on insects and small spiders.
• Eastern Fence Lizard Sceloporus Undulates
Alternate name: Prairie Lizard, Plateau Lizard Family: Phrynosomatidae, Earless and Horned Lizards
Description: 3 1/2-7 1/2" (9.0-19.0 cm). Dark band along rear of thigh. Color varies geographically: gray to brown or rusty, dark or light stripes down back, sometimes vague crossbars or spots. Back and belly scales about same size. Males usually marked by black-bordered blue patches on belly and blue throat patch.
Subspecies:
- Southern Fence Lizard (S. u. undulatus), wavy dark crossbars on back, blue patches on belly and throat; s. South Carolina to c. Florida, west to e. Louisiana.
- Southern Prairie Lizard (S. u. consobrinus), weak dorsolateral light stripes, throat patches often fused, female lacks belly patches; se. Arizona to extreme s. Oklahoma, through c. Texas to Mexico. _White Sands Prairie Lizard (S. u. cowlesi), pale, back pattern faint or absent; White Sands, New Mexico.
- Northern Plateau Lizard (S. u. elongatus), wavy dark crossbars on back, blue patches on throat and belly; sw. Wyoming to ne. Arizona and nw. New Mexico.
- Red-lipped Plateau Lizard (S. u. erythrocheilus), dorsolateral stripes indistinct or absent, blue throat patches meet at midline, chin yellow, lips orange during breeding season; extreme ne. New Mexico and w. Oklahoma through e. Colorado to se. Wyoming.
- Northern Prairie Lizard (S. u. garmani), prominent dorsolateral light stripes, throat patches reduced or absent, female lacks belly patches; se. Wyoming and s. South Dakota through e. Colorado, Kansas and Oklahoma to extreme n. portion of Texas panhandle.
- Northern Fence Lizard (S. u. hyacinthinus), wavy dark crossbars on back, belly and throat patches black-bordered; e. Kansas to New Jersey, south to c. South Carolina, southwest to e. Texas, and north through e. Oklahoma.
- Southern Plateau Lizard (S. u. tristichus), faint dorsolateral light stripes, blue throat and belly patches; c. Arizona to c. New Mexico.
Breeding: Mates April to August. Yearling lays 1 clutch of 3-13 eggs, June to September; older females lay 2-4 clutches. Eggs hatch June to September. Habitat Generally sunny locations: favors rotting logs, open woodlands, open grassy dunes, prairies.
Range: Delaware to Florida and west to New Mexico and Arizona. Discussion Diurnal. In the east this lizard is primarily arboreal, seldom far from a tree or wall up which it will flee to avoid capture. In the prairie states it is more terrestrial, sheltering under brush or in burrows. It will eat almost any insect, spider, centipede, or snail, but beetles seem a favorite food. More about fence lizards of this region from enature.com
• Prairie Skink Eumeces Septentrionalis
Family: Scincidae, Skinks
Description: 5-8 1/8" (13-20.6 cm). Brown, with 4 dark-edged light stripes extending onto tail. Light stripes on side separated by dark band 2 scale rows wide. Upper light stripes follow adjoining edges of 4th and 5th scale rows counting from middle of back. Pale stripe may run down middle of back. Upper labial scales, 7. Breeding male may have orange on head. Young have bright blue tail.
Subspecies:
- Northern Prairie Skink (E. s. septentrionalis), mid-back pale stripe present; S. Manitoba; Minnesota, w. Wisconsin, and se. North Dakota south to c. Kansas.
- Southern Prairie Skink (E. s. obtusirostris), mid-back stripe faint or absent; sc. Kansas to c. Texas and the Gulf Coast.
- The two subspecies are sometimes considered separate species. Some authorities recognize a third subspecies, Pallid Skink (E. s. pallidus). Breeding Mates May to June. Clutch of 5-18 eggs is laid May to July. Habitat Moist terrain with vegetation and loose soil; rocky, gravelly washes.
Range:
S. Manitoba south through e. North Dakota, Minnesota, and w. Wisconsin; south to coastal Texas.
Discussion Active during twilight and predawn hours. Terrestrial; the Prairie Skink is found under rocks, boards, or leaf litter. When disturbed, it retreats into a burrow or disappears into the vegetation. It feeds on insects, spiders, and snails. More about skinks of this region from enature.com
• Eastern Fence Lizard Sceloporus Undulates
Family: Scincidae, Skinks
Description: 5-7 5/8" (12.7-19.4 cm). Long-bodied, with many alternating light and dark stripes, including dorsolateral light stripe along 3rd scale row counting from middle of back. Back striping faded or absent in some populations. Tail tapers so gradually it appears swollen. Young have bright blue tail.
Subspecies:
- Northern Many-lined Skink (E. m. multivirgatus), stripes persistent; sw. South Dakota, se. Wyoming, w. and c. Nebraska to ec. Colorado and n. New Mexico.
- Variable Skink (E. m. gaigeae; sometimes called E. m. epipleurotus), stripes faded or absent in adults; extreme s. Colorado and se. Utah into Arizona, w. Texas, and Mexico.
Breeding:
Lays clutch of 5 eggs. Habitat Areas of rocks and small brush in open grassy plains, sand hills, and desert; mountainous wooded areas to 8,200' (2,500 m).
Range:
Sw. South Dakota through se. Wyoming, south to Arizona and New Mexico; scattered populations in w. Texas and Mexico.
Discussion Diurnal. This skink typically burrows under rocks, logs, trash, even dry cow chips. It feeds on insects.
• Eastern Fence Lizard Sceloporus Undulates
Family: Phrynosomatidae, Earless and Horned Lizards
Description: 3 3/4-6 1/4" (9.3-15.9 cm). Flat-bodied; head crowned by short, stubby, horizontal spines interrupted at rear by deep notch in skull. 1 row of pointed scales fringes trunk. Belly scales smooth. Gray, yellowish, or reddish-brown. Two rows of large dark spots down back; spots may have partial or ill-defined light borders.
Breeding: Litters of 6-31 are born alive, July to August.
Habitat Varies, from open rocky or sandy plains to forested areas; from sea level to above 9,000' (2,700 m).
Range: Montana and adjacent Canada southeast through w. Dakotas, Kansas, and w. Texas and southwest through se. Idaho and e. Nevada, most of Arizona and New Mexico, and south into Mexico.
Discussion Diurnal. This species is most active during the midday warmth. At night it burrows into the soil. It feeds primarily on ants, but occasionally eats other insects, snails, sow bugs, even small snakes. This species was formerly considered a subspecies of P. douglasii; other former subspecies (P. d. brevirostre, P. d. ornatum, and P. d. ornatissimum) are now considered populations of P. hernandesi.
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