Description:Callisaurus draconoides is a relatively large lizard, with males ranging in snout to vent length from 70 mm to 93 mm. Females are slightly shorter, typically ranging from 65 mm to 75 mm. Overall body length in both sexes ranges from 152 to 232 mm. Compared to other species of iguanids, both the tail and hind limbs of C. draconoides are considerably longer. In addition, the tail of C. draconoides is flattened. Subspecies of C. draconoides differ slightly in body measurements, particularly tail and hind leg length relative to overall body size.
Zebra-tailed lizards can be distinguished from similar species by their coloration and markings. Their dorsal surface ranges from gray to brown with yellow blotches. They have dark spots on both sides of their mid-dorsal line that extend from their neck to the bottom of the tail. The limbs and tail have 4 to 8 dark lateral cross bands separated by lighter areas, giving zebra-tailed lizards their distinct “zebra-striped” look. The intensity of coloration typically changes with temperature. Under higher temperature conditions, colors become much lighter; under mid-range temperatures, coloration typically matches that of their habitat.
Zebra-tailed lizards are sexually dimorphic, and males and females show differences in coloration and body markings. Both sexes have dark throats with radiating black lines; however, this pattern is particularly noticeable in males. Males also have sky blue to navy blue patches on both sides of the belly; these give way to two diagonal black bars that fade into brown on the sides of the body. Females are similar to males but lack the black and blue patches on the belly and have only faint black coloration on the sides and body. During breeding season, males exhibit a patch of metallic green-blue, sometimes orange and yellow, on the sides of their bodies and the lighter areas on their throat become pink.
The appearance of juveniles also differs from that of adults. Juveniles have dark dorsal spots that disappear as they age. These spots are completely gone once males reach sexual maturity. Young males also lack the black belly markings present in adult males.
Zebra-tailed lizards are similar, in some regards, to earless lizards and fringe-toed lizards. These three groups are sometimes referred to as “sand” lizards. These genera all have small scales on their heads, small granular scales on their backs, and folds of skin across their throats. In zebra-tailed lizards, these scales vary in size and texture across their bodies. Dorsal scales are small and smooth. Ventral scales are large, smooth, and flat. Scales on the head are small compared to those covering the rest of the body. Unlike earless lizards, both zebra-tailed and fringe-toed lizards have external ear openings. Belly markings also differ among these groups, with fringe-toed lizards having a single large blotched marking on the belly. Both zebra-tailed and earless lizards have two crescent-shaped belly markings. Belly markings in zebra-tailed lizards vary by location, occurring at or in front of their mid-body region.
Habitat:Callisaurus draconoides is a terrestrial lizard that lives in deserts or in semi-arid habitats with lose sandy soil. In rocky areas, this species is limited to sandy washes or occurs among boulders in canyons. In deserts, C. draconoides most often is found on the desert floor among shrubs, which are used for shade; rocks and boulders are used as perches for basking.
As a desert species, zebra-tailed lizards tolerate considerable variability in temperatures and rainfall. Throughout their geographic range, they experience high temperatures during the day and low temperatures at night. In the Mojave desert, temperatures range from 120°F during the day to 20°F at night. In the Great Basin, temperatures range from 57°F to 18°F, and in the Colorado desert, temperatures range from 113°F to 23°F. Because of this extreme temperature variation, zebra-tailed lizards tend to be diurnal, allowing periods of greatest activity during hours when the temperatures are most suitable. In addition, zebra-tailed lizards are capable of dealing with differing rainfall conditions. For example, in the Great Basin, rainfall varies from 2.3 to 3.0 cm per year; in the Mojave desert, it varies from 5.3 to 6.4 cm per year. In contrast, in the Colorado desert, rainfall ranges from 10.2 to 15.2 cm per year.
Range: Zebra-tailed lizards are native to the Nearctic region, occurring throughout the deserts of the southwestern United States and northern Mexico. Their geographic range includes the Mojave, Great Basin, and Colorado deserts. They are especially common in western Texas, southern California, Arizona, southern Utah, Nevada, and northern Mexico.
Diet: Although it is generally characterized as an insectivore, zebra-tail lizards consume plant material and the sloughed skin of other lizards. Common prey includes small invertebrates such as scorpions, flies, ants, spiders, worms, eggs, carrion, and other small vertebrates. Zebra-tailed lizards eat many different types of insect larvae, as well as leaves and flowers found throughout their geographic range. The diet of zebra-tailed lizards varies seasonally and regionally. Northern populations regularly consume grasshoppers during late summer and are more prone to eating vegetation during spring months when compared to other populations. More southerly populations regularly appear to prefer beetles and insect larvae.
Reproduction: Zebra-tailed lizards are polygynous. The bond formed between males and a particular female may be strong or weak. Stronger bonds result in greater territory defense and greater duration of the male-female relationship. Once a bond is formed, the two court briefly, followed by copulation. It benefits males to mate with as many females as possible, typically resulting in higher hierarchical standing or rank. During breeding season, males attract mates by demonstrating that they are superior to other males. To do this, they perch themselves in an exposed area and perform a series of head bobs and push-ups. This is also used as a means of defending their territories. If a male enters another's territory, the resident male becomes highly aggressive.
Breeding season in Callisaurus draconoides begins in May and extends into August. Males reach peak reproductive state from May through July and show enlarged testes during this period. Females typically exhibit peak reproductive state from May through August. Both males and females reach reproductive maturity at about two years of age, with reproductively mature males (average snout-vent length = 70 mm) slightly larger than females (average snout-vent length = 65 mm). Like most other reptiles, C. draconoides is oviparous and has internal fertilization. Gestation lasts for 48 to 62 days. Females lay eggs in sheltered, humid environments to prevent desiccation. Average clutch size is 4 eggs, with each egg approximately 8 x 15 mm in size. Hatchlings are born with an "egg-tooth" - a tooth-like structure on their nose used to slice through the egg, which is lost shortly after hatching. Upon hatching, offspring are smaller but otherwise very similar in appearance to adults. Offspring are immediately independent of their parents.
Status: Listed as Least Concern in view of its wide distribution, presumed large population, and because it is unlikely to be declining fast enough to qualify for listing in a more threatened category.
Subspecies: Nine, with just Four in the United States:
Sinaloa Zebra-tailed Lizard - (Callisaurus draconoides bogerti)
Short-footed Zebra-tailed Lizard - (Callisaurus draconoides brevipes)
Carmen Island Zebra-tailed Lizard - (Callisaurus draconoides carmenensis)
Viscaino Zebra-tailed Lizard - (Callisaurus draconoides crinitus) Common Zebra-tailed Lizard - (Callisaurus draconoides draconoides)
Sonora Zebra-tailed Lizard - (Callisaurus draconoides inusitatus) Nevada Zebratail Lizard - (Callisaurus draconoides myurus) Mojave Zebra-tailed Lizard - (Callisaurus draconoides rhodostictus) Arizona Zebratail Lizard - (Callisaurus draconoides ventralis)
Taxonomy: The genus Callisaurus is monotypic, containing only one species, C. draconoides. Nine subspecies are recognized.
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Disclaimer: ITIS taxonomy is based on the latest scientific consensus available, and is provided as a general reference source for interested parties. However, it is not a legal authority for statutory or regulatory purposes. While every effort has been made to provide the most reliable and up-to-date information available, ultimate legal requirements with respect to species are contained in provisions of treaties to which the United States is a party, wildlife statutes, regulations, and any applicable notices that have been published in the Federal Register. For further information on U.S. legal requirements with respect to protected taxa, please contact the U.S. Fish and Wildlife Service.