Desert Banded Gecko

P. Cooper

Scientific Name: Coleonyx variegatus variegatus
Description: 4 1/2 - 6 inches. Soft, pliable skin. Vertical pupils. Movable eyelids. Scalation finely granular, toes slender, and tail constricted at base. Brown bands on both body and tail, on a pink to pale yellow background. The bands tend to break up with age or in certain localities into a blotched, spotted, or mottled pattern. Body bands same width as or narrower than interspaces between them; bands with light centers, or replaced by spots. Light collar mark indistinct or absent. Head spotted. Plain whitish below. May squeak when caught. Young: Brown bands above usually well defined and unbroken. Male: Prominent spur on each side at base of tail. Spurs weak or absent in female. Usually 7 or fewer preanal pores, in contact at ventral midline. Corresponding scales in female usually enlarged and sometimes pitted.
Habitat: Creosote bush flats and sagebrush desert to the pinyon-juniper belt; chaparral areas. Often associated rocks, may seek shelter under them or in crevices. In some parts of its range, it occurs on barren dunes.
Habits: Nocturnal; subterranean. When stalking prey, it waves its tail like a prowling cat. A constriction at the tail's base marks the place where it breaks away when grabbed.
Reproduction: 1-3 clutches, usually of 2 eggs, laid May-September.
Diet: Insects and spiders.
Notes: To find these lizards, drive slowly along blacktop roads and watch for a small, pale, twiglike form. In the daytime turn over rocks, boards, and other objects, especially in spring before ground surfaces heat up.

Tucson Banded Gecko

Scientific Name: Coleonyx variegatus bogerti
Description: 2-3 inches. Soft, pliable skin. Vertical pupils. Movable eyelids. Scalation finely granular, toes slender, and tail constricted at base. Brown bands on both body and tail, on a pink to pale yellow background. The bands tend to break up with age or in certain localities into a blotched, spotted, or mottled pattern. Body bands same width as or narrower than interspaces between them; bands with light centers, or replaced by spots. Light collar mark indistinct or absent. Head spotted. Plain whitish below. May squeak when caught. Young: Brown bands above usually well defined and unbroken. Male: Prominent spur on each side at base of tail. Spurs weak or absent in female. Usually 8 or more preanal pores, in contact at ventral midline. Corresponding scales in female usually enlarged and sometimes pitted.
Habitat: Creosote bush flats and sagebrush desert to the pinyon-juniper belt; chaparral areas. Often associated rocks, may seek shelter under them or in crevices. In some parts of its range, it occurs on barren dunes.
Habits: Nocturnal; subterranean. When stalking prey, it waves its tail like a prowling cat. A constriction at the tail's base marks the place where it breaks away when grabbed.
Reproduction: 1-3 clutches, usually of 2 eggs, laid May-September.
Diet: Insects and spiders.
Notes: To find these lizards, drive slowly along blacktop roads and watch for a small, pale, twiglike form. In the daytime turn over rocks, boards, and other objects, especially in spring before ground surfaces heat up.

Common Chuckwalla

Scientific Name: Sauromalus obesus
Description: 5 - 9 inches. Large, flat, dark-bodied lizard with loose folds of skin on neck and sides. Often seen sprawled on a rock in the sun. Skin on back covered with small granular scales. Tail with blunt tip and broad base. Rostral scale absent. Young: Crossbands on body and tail. Bands on tail conspicuous—black on olive-gray or yellowish background. Male: Head, chest, and limbs usually black, sometimes spotted and flecked with pale gray. Back black, red, or light gray, depending on age and locality. Tail usually cream-colored or pale yellow. Tail orange in adult males from South Mountain south of Phoenix, AZ. Some individuals may have torso suffused with red. Female: Tends to retain juvenile crossbands.
Habitat: Rock-dwelling. Desert. Creosote bush common in its range. Nearly every lava flow, rocky hillside, and outcrop will have its chuckwallas. Rocks provide shelter and basking sites.
Habits: Diurnal. On emerging in the morning, this lizard basks until its preferred body temperature of 100 degrees Fahrenheit is reached, then it begins searching for food.
Reproduction: Clutch of 5-16 eggs, laid June to perhaps August. Females may lay only every second year.
Diets: Herbivorous. Variety of desert annuals, some perennials, and occasionally insects.
Notes: To find this lizard, drive on desert roads in late morning and afternoon to spot basking individuals among the rocks. Approach on foot and take note of the crevice the lizard enters, or listen for the sandpaper-like sound made as it slides into a crack. Look for droppings (elongate, cylindrical pellets containing plant fibers), which mark basking sites and favored retreats. Shine a flashlight into the crevice to see the "chuck" in its retreat. When disturbed, chuckwallas gulp air, distend their body, and wedge themselves tightly in place. It can sometimes be coaxed into backing out of the crack by repeatedly tapping its snout with a stick.

Desert Iguana

Scientific Name: Dipsosaurus dorsalis
Description: 10-16 inches. Large, pale, round-bodied lizard with a long tail and a rather small, rounded head. A row of slightly enlarged, keeled scales down middle of back. Pale gray above, with barring or network of brown on sides; variously spotted and blotched with light gray. Pale below, with pinkish to buff areas on sides of belly in both sexes during breeding season.
Habitat: Creosote bush desert with hummocks of loose sand and patches of firm ground with scattered rocks. In the south it frequents subtropical scrub. Most common in sandy habitats but also occurs along rocky streambeds, on bajadas, silty floodplains, and on clay soils.
Habits: Diurnal. May be seen basking on rocks or sand hummocks, near a burrow in which it may take refuge. Tolerant of high temperatures, remaining out on hot, sunny days when most other lizards seek shelter; active even at 115 degrees Fahrenheit. When surface temperatures do get too hot for them, they climb into bushes to reach cooler air layers. Wary lizards that flee to the nearest rodent burrow or bush at the slightest hint of danger.
Reproduction: Breeds April-July. Clutch of 3-8 eggs, laid June-August. Hatchlings appear August to September.
Diet: Chiefly herbivorous. Climbs among the branches of the creosote bush and other plants to obtain fresh leaves, buds, and flowers. It also eats insects, carrion, and its own fecal pellets.

Lesser Earless Lizard

P. Cooper

Scientific Name: Holbrookia maculata
Description: 4 - 5 1/8 inches. Small, ground-dwelling lizard with no ear openings. Smooth, granular scales above. A fold of skin across the throat. Tail short; no black bars on underside. Ground color brown, tan, gray, or whitish above, usually closely matching the soil color of the habitat. Back usually marked with scattered light spots and 4 lengthwise rows of dark blotches, each blotch pale-edged at rear. A pair of black marks on each side of belly. Light-bordered dark stripe on rear of thighs. Male: Enlarged postanal scales. Dark blotches on back often faint; usually light-edged when present. Belly markings more conspicuous than in female and set off by blue borders. Female: Often develops a vivid orange or yellow patch on the throat during the breeding season.
Habitat: Primarily a plains lizard, most common where there are exposed patches of sand or gravel. Frequents washes, sandy streambanks, sand dunes, shortgrass prairie, mesquite and pinyon-juniper woodland, sagebrush flats and farmland.
Habits: Diurnal. Loss of the external ear may be an adaptation to this lizard's habit of burrowing headfirst into sand.
Reproduction: 1 or 2 clutches of 1-12 eggs, laid April-September.
Diet: Insects, spiders, and small lizards.
Notes: Not a particularly fast runner; can sometimes be caught by hand.

Greater Earless Lizard

Scientific Name: Cophosaurus texanus
Description: 1 7/8 - 3 1/2 inches. Slim-legged lizard with a long, flat tail that has black crossbars on the underside (bars missing if tail regenerated). Ground color above tends to blend with the soil color of the habitat and may be gray, brown, or reddish, with numerous small light flecks. Each side of belly marked with 2 black or sooty crescents, which extend up onto sides. Black markings behind midpoint of body. No ear openings. Light-bordered dark stripe on rear of thigh. Dorsal scales granular. Diagonal furrows between upper labials. Gular fold present. Male: Enlarged postanal scales. Black crescents bordered by blue or greenish on belly and by yellowish on flanks. Female: Dark crescent-shaped markings faint or absent. During the breeding season some females develop a pinkish wash, especially on flanks, and a vivid orange throat patch.
Habitat: Middle elevations, avoids extreme desert lowlands and the higher mountains. Common among cactus, mesquite, ocotillo, creosote bush, and paloverde. Prefers sandy, gravely soil of flats, washes, and intermittent stream bottoms where plants are sparse and there are open areas for running. Occasionally found on rocky hillsides. Sometimes runs with tail curled over body.
Habits: Diurnal. An exceptionally active lizard, constantly dashing from rock to rock as it surveys its territory and hunts insect prey. Sometimes runs with its tail curled over the body.
Reproduction: Clutches of 2-9 eggs each, laid March-August.
Diet: Insects (grasshoppers, caterpillars, bees, wasps, etc.) and spiders.

Zebra-tailed Lizard

P. Cooper

Scientific Name: Callisaurus draconoides
Description: 6 - 9 1/8 inches. Slim-bodied lizard with a long, flat tail and extremely long, slender legs, well adapted for running at high speed. Ear openings present. Black crossbars on white undersurface of tail (the "zebra" markings). Gular fold present. A gray network on back and dusky crossbars on upper surface of tail. Sides usually lemon yellow. 2 or 3 black or gray bars on each side of belly, extending slightly up the sides. Black belly markings at or in front of midpoint of body. Light-bordered dark stripe on rear of thigh. Throat dusky, often with a pink or orange spot at center. Male: Enlarged postanal scales. Belly markings conspicuous and located in blue patches on each side of belly. Female: Belly markings faint or absent.
Habitat: Washes, desert "pavements" of small rocks, and hardpan, where plant growth is scant and there are open areas for running. Occasionally found in rocky arroyos and on fine windblown sand, but usually not far from firm soil.
Habits: Diurnal. When about to run, it curls and wags its tail; it runs at great speed, with the tail curled forward. The bold tail markings may divert the attack of hawks or other predators to the tail, which can be regenerated.
Reproduction: 1 to perhaps 5 clutches (more in southern part of range) of 2-15 eggs, laid June-August.
Diet: Insects, spiders, other lizards, and occasionally plants.

Long-nosed Leopard Lizard

Scientific Name: Gambelia wislizenii
Description: 3 1/4 - 5 3/4 inches. A large lizard with many large dark spots, a rounded body, a long round tail, and a large head. Dorsal scales granular. Capable of marked color change: in dark phase, spots are nearly hidden and light crossbars are conspicuous on both body and tail; in light phase the reverse is true. Ground color gray, pinkish, brown, or yellowish brown above. Throate streaked or spotted with gray. Scales on top of head small, including interparietal. Young: Markings, especially crossbars, usually more contrasting than in adults; upper back often rust-colored. Young of some populations have bright crimson spots. Male: Usually smaller than female. Female: During breeding season, reddish orange color appears on underside of tail, and as spots and bars on sides of neck and body. The reddish color disappears after the breeding season.
Habitat: Arid and semiarid plains grown to bunch grass, alkali bush, sagebrush, creosote bush, or other scattered low plants. The ground may be hardpan, gravel, or sand. Rocks may or may not be present. Avoids dense grass and brush, which interfere with running.
Habits: Diurnal. An agile lizard that darts from bush to bush in search of insects, though it often lies in wait for insect or lizard prey in the shade of a bush, where its spotted pattern blends in. Tap bushes with a stick to flush these lizards. They run with forelimbs raised when running fast. Will attempt to bite when caught.
Reproduction: Clutch of 1-11 eggs, laid March-July. a second clutch may be laid in the south.
Diet: Insects (grasshoppers, crickets, beetles, termites, butterflies, caterpillars, bees, wasps), spiders, lizards, snakes, small rodents (pocket mice), and soft leaves, blossoms, and berries.

Eastern (Common) Collared Lizard

P. Cooper

Scientific Name: Crotaphytus collaris
Description: 3 - 4 3/5 inches. Robust lizard with a relatively large, broad head; a short snout; and a long, rounded tail. Two dark collars: the first (anterior) one is of equal width throughout or narrows at sides and does not encircle throat; the second (posterior) one often reaches the forelimbs in males, less often in females. Numerous light spots and often a series of dark crossbands on body. Ground color above varies -- may be greenish, bluish, olive, brown, or yellowish, depending on locality, sex, age, and color phase. Markings tend to fade with age, the collar least. Throat spotted. Mouth and throat lining usually black. Some greenish reflections usually present on upper surfaces over most of range. Dorsal surface of tail usually spotted and crossbanded. Belly whitish or cream. Head yellow or whitish; if yellow, color does not extend under chin or behind supraorbital semicircles. Young: Broad dark crossbands or transverse rows of dark spots on body and tail. Sometimes with red or orange markings like breeding female's. Male: Usually considerable greenish color on dorsal surfaces, including sides and limbs. Throat dark-spotted—little or no green or blue coloring. Enlarged postanal scales. Female: Lacks or has slight tinge of green above. Throat unmarked or lightly spotted with brown or gray. In breeding season, develops spots and bars of red or orange on sides of neck and body, which fade after the eggs are laid.
Habitat: Rock-dwelling. Canyons, rocky gullies, limestone ledges, mountain slopes, and boulder-strewn alluvial fans, usually where vegetation is sparse. Essentials appear to be boulders for basking and lookouts, open areas for running, and adequate warmth.
Habits: Diurnal. A wary, feisty lizard that will bite readily and hard, given the chance. Jumps nimbly from rock to rock and seize other lizards and insects with a rush, often running with their forelimbs lifted off the ground and the tail raised, giving it the appearance of a fierce little dinosaur.
Reproduction: 1-2 clutches of 1-14 eggs, laid April-July.
Diet: Insects, lizards, and occasionally berries, leaves, and flowers.
Notes: Most are easily caught in the morning when they bask at the top of boulders. To avoid being bitten, handle these lizards by the sides of the head.

Desert Spiny Lizard

Scientific Name: Sceloporus magister
Description: 3 1/4 - 5 3/5 inches. Stocky, usually light-colored lizard with large, pointed scales and a black wedge-shaped mark on each side of the neck. Rear edge of neck markings whitish or pale yellow. Straw-colored, yellow, yellowish brown, or brown above, with crossbands or spots of dusky that usually fade with age. Sides often tinged with rust. Head sometimes orange. 5-7 pointed ear scales (auriculars). Supraorbital semicircles incomplete. Young: Usually with many small blotches arranged in 4 lengthwise rows. Crossbands often conspicuous. Male: Dorsal markings vary with subspecies. Enlarged postanals and swollen tail base. Blue-green patch on throat and on each side of belly. Belly patches edged with black and sometimes joined at midline. Female: Blue markings weak or absent. Head orange or reddish when breeding.
Habitat: Arid and semiarid regions on plains and lower slopes of mountains. Found in Joshua-tree, creosote-bush, and shad-scale deserts, mesquite-yucca grassland, juniper and mesquite woodland, subtropical thornscrub, and along rivers grown to willows and cottonwoods.
Habits: Diurnal. Wary lizards that dart into rocky crevices, rodent holes, or vegetative cover when startled. They readily climb trees or walls in search of insect prey. Often bites when captured.
Reproduction: Clutch of 4-19 eggs, laid May-August; more than 1 clutch may be laid per season.
Diet: Insects, spiders, lizards, and occasionally buds, flowers, berries, and leaves.

Clark Spiny Lizard

Scientific Name: Sceloporus clarkii
Description: 7 1/2 - 12 inches. A large, often wary lizard, usually only glimpsed as it scrambles to the opposite side of a limb or tree trunk. Gray, bluish green, or blue above, with dusky or black bands on wrists and forearms. Black shoulder mark. Irregularly crossbanded with dark and light markings, which may become faint or disappear, especially in old males. Projecting spine-tipped scales on body. Young: Crossbands on body and tail. Male: Enlarged postanals and swollen tail base. Throat patch and sides of belly blue. Female: Blue markings usually weak or absent.
Habitat: Chiefly lower mountain slopes in oak-pine woodland, tropical deciduous forest, and subtropical thornforest. Prefers more humid environments, generally at higher elevations.
Habits: Diurnal. More at home in trees than on the ground. It takes refuge in rat nests built among the tree limbs.
Reproduction: Clutch of 4-24 eggs, laid May-November; sometimes more than 1 clutch may be laid each season.
Diet: Insects and occasionally leaves, buds, and flowers.
Notes: Often heard before it is seen. Two people are usually required to keep these lizards in sight because they tend to stay on the opposite side of rocks and tree trunks. To noose them usually requires careful stalking while a companion diverts their attention.

Southern Plateau Lizard

Scientific Name: Sceloporus undulatus tristichus
Description: 3 1/2 - 7 1/2 inches. Gray, brown, reddish, or nearly black above, with pattern of crossbars, crescents, or lengthwise stripes. Striped patterns are prevalent in the Great Plains area. Light stripes usually present on back. Blue on throat usually divided, often into 2 widely separated patches, a characteristic that distinguishes this lizard from the Western Fence Lizard. Male: Enlarged postanals, swollen tail base. Breeding male has intense blue patches on throat and sides of belly. Throat patches are separate or joined in male. When in light phase, dorsal scales become blue or greenish. Female: Often has pale blue patches on belly. Throat patches are separate in female.
Habitat: Forests, woodland, prairie, shrubby flatlands, sand dunes, rocky hillsides, and farmlands. Seeks shelter in bushes, trees, old buildings, woodpiles, rodent burrows, and under rocks, logs, or other objects on the ground. In forested parts of its range it climbs trees, and when frightened keeps to the opposite side of the trunk. Where trees are scarce this lizard is primarily a ground dweller.
Habits: Diurnal. Active throughout the year in the southern part of its range.
Reproduction: 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.
Diet: Insects, spiders, ticks, millipedes, snails, and small lizards. Beetles seem a favorite food.

Ornate Tree Lizard

P. Cooper

Scientific Name: Urosaurus ornatus
Description: 4 1/2 - 6 1/4 inches. A slim, dark brown, black (when in dark phase), tan, sooty, or gray lizard with small scales and a long, slender tail. Often a rusty area at the base of the tail. A gular fold. Band of enlarged scales down middle of back, separated into 2 or more parallel rows by center strip of small scales. Above usually blotched or crossbarred with dusky. A fold of skin on each side of body. Male: Vivid blue or blue-green belly patches, sometimes united and occasionally connected with blue throat patch. Throat sometimes yellow, greenish, or pale blue-green. Female: Throat whitish, orange, or yellow. No belly patches.
Habitat: Climbing lizard that spends much of its time in trees and on rocks. Sometimes seen clinging head downward. Its color often blends with the background. Frequents mesquite, oak, pine, juniper, alder, cottonwood, and non-native trees such as tamarisk and rough-bark eucalyptus, but also may occur in treeless areas. Appears to be especially attracted to river courses. Ranges from desert to the lower edge of the spruce-fir zone.
Habits: Diurnal. Often found in pairs or groups. Shy and wary, it is adept at hiding by agilely keeping a tree trunk or branch between itself and a pursuer. Most often found in the morning and late afternoon. When encountered on the ground, it may run to a rock or tree and climb upward, keeping out of sight.
Reproduction: 1-6 (higher counts in the south) clutches, each of 2-13 eggs, laid March-August.
Diet: Insects, spiders, and centipedes.

Long-tailed Brush Lizard

P. Cooper

Scientific Name: Urosaurus graciosus
Description: 1 7/8 - 2 3/5 inches. Well-camouflaged, shrub- or tree-dwelling lizard that often lies motionless, with its slim body aligned with a branch. Tail long and slender—often twice as long as body. Gray above, with dusky to black crossbars, but when captured may change color from dark gray to pale beige in less than 5 minutes. A pale lateral stripe usually extends from the upper jaw along each side of the neck and body. A broad band of enlarged scales down middle of back. Well-developed gular fold. Frontal usually divided. Male: A pale blue or greenish patch flecked with white on each side of the belly, lacking in female. Both sexes may have a reddish, orange, or lemon yellow throat.
Habitat: Desert species. Frequents areas of loose sand and scattered bushes and trees, creosote bush, burrobush, galleta grass, catclaw mesquite, and paloverde. Creosote bushes with exposed roots seem to be especially favored, perhaps because of the shelter afforded by the root tangle.
Habits: Diurnal. At night and on windy days it may seek shelter in the sand or in burrows of other animals.
Reproduction: 1 or perhaps 2 clutches of 2-10 eggs, laid May-August.
Diet: Insects, spiders, and occasionally parts of plants.
Notes: Since these lizards resemble bark and tend to remain motionless when approached, carefully examine branches of bushes and trees to find them. Search the lower bare branches of creosote bushes on the side facing early morning sun. Although this lizard is diurnal, after a hot day it may sleep aloft and can be found by searching the tips of branches at night.

Side-blotched Lizard

P. Cooper

Scientific Name: Uta stansburiana
Description: 4 - 6 3/8 inches. A small, often brownish lizard with a bluish black blotch on each side of the chest, behind the forelimb; side blotch occasionally faint or absent. Ground color above brown, gray, or yellowish to nearly black—blotched, speckled, or sometimes unpatterned. Populations with little or no dorsal pattern are widespread in some areas. Whitish to bluish gray below, sometimes with orange to reddish orange on throat and sides of belly. A gular fold. Scales on back small and smooth, without spines at end. Frontal divided. Male: Slightly enlarged postanals; swollen tail base. In light phase, speckled above with pale blue. No distinct blue belly patches. Female: Blotched with brown and whitish, occasionally striped. No blue speckling. Side blotch usually less well-defined than in male.
Habitat: One of the most abundant lizards in the arid and semiarid regions of the West. The habitat varies—sand, rock, hardpan, or loam with grass, shrubs, and scattered trees. Often found along sandy washes where there are scattered rocks and low-growing bushes. Chiefly a ground-dweller, active all year in the south.
Habits: Diurnal. They are active on any warm day throughout the year in the southern regions.
Reproduction: Eggs laid March-August. In the north, female lays 1-3 clutches of 1-5 eggs, and in the south 2-7 clutches, each of 1-8 eggs.
Diet: Insects, scorpions, spiders, mites, ticks, and sowbugs.

Short-horned Lizard

P. Cooper

Scientific Name: Phrynosoma douglassii
Description: 2 1/2 - 5 7/8 inches. Short, stubby horns and single row of fringe scales on each side of the body. Throat scales all small. Beige, gray, brown, reddish, or tan above, blotched with dark brown and often speckled with whitish; the color pattern usually closely matches the background. A pair of large dark brown blotches on back of neck. Rear of throat and chest usually buff or orange-yellow.
Habitat: Semiarid plains high into the mountains. Shortgrass prairie, sagebrush, open pinyon-juniper, pine-spruce, and spruce-fir forests. The ground may be stony, sandy, or firm, but usually some fine loose soil is present. More cold-tolerant than other horned lizards.
Habits: Diurnal. Most active during midday warmth. At night it burrows into the soil.
Reproduction: Live-bearing; 5-36 young, born July-September.
Diet: Insects (including ants), spiders, snails, and even small snakes.

Desert Horned Lizard

Scientific Name: Phrynosoma platyrhinos
Description: 2 5/8 - 3 3/4 inches. Snout very blunt. Horns and body spines relatively short. One row of well-developed fringe scales on each side of body, and 1 row of slightly enlarged scales on each side of the throat. General coloration resembles the soil color of the habitat—beige, tan, reddish, gray, or black, the latter in individuals found on black lava flows. Wavy dark blotches on back and a pair of large dark blotches on neck.
Habitat: Arid lands, sandy flats, alluvial fans, along washes, and at edges of dunes. Sometimes found on hardpan or among rocks, patches of sand are generally present. Creosote bush, saltbush, greasewood, cactus, ocotillo in the desert; Basin sagebrush, saltbush, and greasewood in the Great Basin.
Habits: Diurnal. If discovered in the open this lizard usually sits quietly, depending on camouflage for safety. When near vegetation, it will dash for cover under the nearest bush. If provoked it hisses, threatens to bite.
Reproduction: 1-2 clutches of 2-16 eggs, laid May-July, perhaps to August.
Diet: Ants, other insects, spiders, and some plant materials (berries, etc.).
Notes: To find these lizards, drive slowly along little-traveled roads in the morning or late afternoon. Watch for them on the pavement and on rocks or earth banks along the roadside where they bask. Usually easily caught by hand.

Regal Horned Lizard

Scientific Name: Phrynosoma solare
Description: 3 1/2 - 6 1/2 inches. 4 large horns at rear of head. Horn bases in contact. Large light-colored area on back—light gray, beige, or reddish, bordered on each side by a broad dusky band. Sometimes a pale middorsal stripe. A single row of fringe scales on each side of body.
Habitat: Rocky and gravely habitats of arid and semiarid plains, hills, and lower slopes of mountains. Much of its range is in succulent plant habitat of upland desert. Plants present may include cactus (saguaro, etc.), mesquite, and creosote bush. Seldom found on sandy flats.
Habits: Diurnal. Most active during early morning, and just before sunset. When caught it may become rigid, with lungs deflated and legs extended. If set down in this condition, it will flop on to its back. Some will squirt blood from the corner of the eye.
Reproduction: Clutch of 7-28 eggs, laid July-August.
Diet: Chiefly ants.
Notes: Search the ground near scrubby plant growth along washes, both in rocky canyons and on the plains. Usually not found in the same habitat with other species of horned lizards.

Great Plains Skink

Scientific Name: Eumeces obsoletus
Description: 6 1/2 - 13 3/4 inches. The largest skink. Oblique scale rows on the sides of the body. Light gray, olive-brown, or tan above, usually profusely spotted with black or dark brown, the spots uniting here and there to form scattered lengthwise lines. Occasionally spotting is absent. Sides generally flecked with salmon. Ground color of tail and feet yellowish or pale orange. Pale yellow below, unmarked. Young: Black above, dark gray below. Tail blue. Orange and white spots on head. With growth the black pigment fades and becomes limited to the rear edge or sides of the scales.
Habitat: Grassland and woodland from the plains into the mountains. In the eastern and central part of its range this skink is chiefly a prairie species, most abundant in open habitats with low vegetation. In the West it enters semiarid environments of canyons, mesas, and mountains, usually where there is grass and low shrubby growth. Rocky outcrops near thickets along permanent or intermittent streams are especially favored. Usually found on fine-grain loose soils, under rocks, logs, bark, and boards.
Habits: Diurnal. A secretive, nervous species that usually attempts to bite when caught.
Reproduction: Nests beneath sunken rocks and tends its eggs. Clutch of 7-21 eggs, laid May-July.
Diet: Insects, spiders, mollusks, and lizards.

Variable Skink

Scientific Name: Eumeces multivirgatus epipleurotus
Description: 5 - 7 5/8 inches. Slim, short-limbed, long-bodied skink with a very long tail. Coloration highly variable; striped, intermediate, and plain-colored (unstriped) forms occur. Striped individuals usually darker (typically olive-brown) and have two dark-edged, prominent, white dorsolateral stripes. Additional dark stripes may be present on sides but in most large adults all may be greatly reduced. Dark stripes on body commonly form zigzag lines. Young: Dorsum dark with 3 bold light stripes; tail bright blue. Male: May develop bright orange or red lips during breeding season.
Habitat: Frequents chiefly rocky, partially wooded areas in mountains, ranging into pine and spruce forests.
Habits: Diurnal.
Reproduction: Clutch of 3-7 eggs, laid May-June and tended by female.
Diet: Mainly insects.
Notes: Look for this skink under rocks, logs, boards, and dried cow chips.

Desert Grassland Whiptail

Scientific Name: Cnemidophorus uniparens
Description: 6 1/2 - 9 3/8 inches. Small whiptail with 6-7 dorsal stripes; dark fields black, dark brown, or reddish brown, without light spots. Tail greenish olive to bluish green. Usually 3 enlarged, rounded scales in front of vent. Young: Tail bright blue.
Habitat: Lowland species of desert and mesquite grassland, but follows drainages into the mountains, where it occurs in evergreen woodland, as at Oak Creek, Arizona. Generally found on plains and gentle foothill slopes, occasionally in areas with cant cover of grasses and herbs, but more commonly where mesquite and yucca are present and often were mesquite is dense.
Habits: Diurnal.
Reproduction: Unisexual—ALL FEMALE—No mating. Clutch of 1-4 eggs, laid May-July; hatches in 50-55 days.
Diet: Insects.

Gila Spotted Whiptail

Scientific Name: Cnemidophorus flagellicaudus
Description: 8- 12 inches. 6 stripes, upper ones tending to become gold or greenish yellow on neck. Traces of a middorsal stripe rarely present. Dark fields coffee brown to blackish, sometimes rust. Yellowish to golden or light beige spots on back, present in both dark fields and touching or located within the pale stripes, especially the paravertebral stripes. Tail light olive-green, sometimes with bluish cast. Whitish to cream below, unmarked. Usually 2 preanals (most whiptails have 3). Young: Hatchlings lack spots.
Habitat: Pinyon-juniper and oak woodlands, chaparral, streamside growth, and the upper edge of desert grassland.
Habits: Diurnal.
Reproduction: Unisexual—ALL FEMALE—No mating.

Sonoran Spotted Whiptail

Scientific Name: Cnemidophorus sonorae
Description: 8-11 inches. 6 stripes. Sometimes a trace of middorsal stripe on neck and lower back. Dark fields blackish, brown, to reddish, with spots of white, pale tan, or dull yellowish. Pale stripes lack light spots. Tail usually dull orange-tan, often grading to olive toward tip. Whitish to cream below, unmarked. Usually 3 preanals (enlarged scales in front of vent). Young: Hatchlings lack spots in dark fields.
Habitat: Upland habitats of oak-woodland and oak-grassland; also in streamside woodland, desert-grassland, desert-scrub of paloverde and saguaro, and thornscrub.
Habits: Diurnal.
Reproduction: Unisexual—ALL FEMALE—No mating.

Plateau Striped Whiptail

Scientific Name: Cnemidophorus velox
Description: 8 - 10 3/4 inches. 6-7 dorsal stripes; when present, middorsal stripe less distinct than the others. Few spots, if any, in black to blackish brown dark fields in either young or adults. Tail light blue. Whitish below, unmarked or with a tinge of bluish, especially on the chin. More than 3 enlarged, angular scales in front of vent. Young: Bright blue tail.
Habitat: Mountains in pinyon-juniper grassland, open chaparral, oak woodland, and lower edges of ponderosa pine and fir forests. At lower elevations, this whiptail frequents broadleaf woodlands along permanent and semipermanent streams.
Habits: Diurnal. While it is foraging in leaf litter beneath bushes this lizard can be approached quite closely before it takes flight. Even then, it may flee only a short distance.
Reproduction: Unisexual—ALL FEMALE—No mating. Clutch of 3-5 eggs, laid June-July. Hatches in August.
Diet: Insects.

Madrean Alligator Lizard

Scientific Name: Gerrhonotus kingii
Description: 7 1/2 - 12 1/2 inches. Belly with scattered dusky spots and bars; usually no lengthwise stripes. Pale gray, beige, or brown above, with distinct wavy crossbars, 8-11 between back of head (marked by ear openings) and front of thighs. Eyes orange or pink. Conspicuous black and white spots on upper jaw. Scales smooth or weakly keeled. Young: Contrasting dark crossbars on back and tail.
Habitat: Mountains; chaparral, oak woodland, pine-fir forests in rocky places near permanent or temporary streams. May also occur in broadleaf stream-border habitats along major drainageways in desert and grassland.
Habits: Diurnal. Primarily a ground-dweller.
Reproduction: Clutch of 9-15 eggs, laid June-July.
Diet: Insects and scorpions.
Notes: Found under logs, rocks, and in woodrat nests and leaf litter in and near dense plant growth. Sometimes abroad at dusk or after dark. Chiefly ground-dwelling but occasionally climbs.

Reticulate Gila Monster

Scientific Name: Heloderma suspectum
Description: 18-24 inches. Large, heavy-bodied lizard with a short swollen tail and a gaudy pattern of black and pink, orange, or yellow. Dorsal surfaces with bead-like scales. Loose folds of skin on neck. Well-developed gular fold. Unusual among lizards in having 4th toe nearly the same length as 3rd toe. Dark forked tongue flicks out in snake-like fashion.
Habitat: Shrubby, grassy, and succulent desert; occasionally enters oak woodland. Lower slopes of mountains and nearby plains and beaches (Sonora). Canyon bottoms or arroyos with permanent or intermittent streams, where it digs burrows or uses those of other animals. Also seeks shelter in mammal burrows, woodrat nests, dense thickets, and under rocks. Prefers irrigated lands or rocky areas grown to scattered bushes. Chiefly ground-dwelling. The color pattern helps conceal this lizard in dim light. On dark backgrounds the black markings blend in and the light markings look like sticks and rocks, while on pale backgrounds the disruptive dark markings may delay recognition of the animal's shape.
Habits: Primarily nocturnal, although also active on warm winter or spring days. Their bite serves to overpower animal predators and prey.
Reproduction: Clutch of 1-8 eggs (Possibly to a dozen), laid July-August.
Diet: Small mammals; eggs, chiefly of ground-nesting birds (quail, mourning doves) and reptiles, lizards, insects, and carrion.
Venomous: The bite of these lizards is tenacious and extremely painful; though rarely fatal to humans. Produced in glands lying along the lower jaw, the venom is not injected like that of a snake but flows into the open wound as the lizard chews on its victim. Most prey is small enough to be taken easily without venom.

Sources:

Behler, John L. and F. Wayne King. National Audubon Society Field Guide to North American Reptiles and Amphibians. Alfred A. Knopf, Inc. 1996.

Conant, Roger and Joseph T. Collins. A Field Guide to Reptiles and Amphibians of Eastern and Central North America—Third Edition, Expanded. Houghton Mifflin Company. 1998.

Ernst, Carl H. Venomous Reptiles of North America. Smithsonian Institution Press. 1992.

Klauber, Laurence M. Rattlesnakes: Their Habits, Life Histories, and Influence on Mankind. University of California Press. 1982.

Pough, F. Harvey, Robin M. Andrews, John E. Cadle, Martha L. Crump, Alan H. Savitzky, and Kentwood D. Wells. Herpetology. Prentice Hall. 1998.

Stebbins, Robert C. A Field Guide to Western Reptiles and Amphibians—Second Edition. Houghton Mifflin Company. 1985.