During the past two years, especially in 1994, large numbers of ornate spiny-tailed lizards (Uromastyx ornatus) were imported into the United States from Egypt. This medium-sized lizard, reaching lengths up to 12 inches, is found in the desert regions of Egypt, Sinai and northern Arabia. Unfortunately, there is little published information about this species, but they are believed to come from rocky desert habitats where they dig burrows.
The genus Uromastyx is a member of the Old World lizard family Agamidae. There are 15 species distributed from northwestern India throughout southern Western Asia and the Arabian Peninsula to the Saharan region of Africa and the arid region of coastal Ethiopia and Somalia (Moody 1987). Only a few species of this herbivorous (plant-eating) lizard are occasionally imported into the United States. In addition to ornate spiny tailed lizards, other species sporadically available are Uromastyx acanthinurus, Uromastyx aegyptius, Uromastyx hardwicki, Uromastyx benti and Uromastyx ocellatus. Some taxonomists consider Uromastyx ornatus to be a subspecies of Uromastyx ocellatus, but for this article we will consider the separate species. All of these lizards have well-armored tails that help protect them from predators, and occasionally herpetoculturists.
The largest member of the genus is the Egyptian spiny-tailed lizard (Uromastyx aegyptius) that grows up to 30 inches long. As adults, these animals are a dark grayish brown with no distinguishing patterns, however their color can lighten when their body temperature is elevated. This big lizard was imported in large numbers during the past few years and some private herpetoculturists and several zoos (Christie 1993) have already bred them.
The North African spiny-tailed lizard (Uromastyx acanthinurus) is a medium-sized lizard that can reach a total length of 15 inches. This large-bodied lizard comes in a variety of spectacular colors, such as red, orange, green or yellow. Two private breeders (Matt Moyle and Bob Mailloux, personal communication) in the United States and one in the United Kingdom (Thatcher 1990) as well as the Oklahoma City and Ft. Worth Zoos (Wheeler 1988), have had sporadic success breeding this beautiful lizard over the last few years. Although occasionally available a few decades ago, this species is seldom imported into the United States.
Most of the other thirteen members of the genus are smaller in total length and less robust than either the Egyptian or North African spiny-tailed lizards. Uromastyx hardwicki is similar in color to the Egyptian spiny-tailed, whereas Uromastyx benti males have burnt red coloration on their backs. Uromastyx ocellatus is usually light brown with light colored spots on the back. I am not aware of anyone having bred any of these species in the United States.
Besides North African spiny-tailed lizards, ornate spiny-tailed lizards are the most spectacularly colored of the imported Uromastyx. Males are green, or bluish green, with patterns of yellow and red on the back and shoulders. Females are more subdued in color but they will often have flecks of red or yellow spots. The vivid coloration of males is not obtained until they reach sexual maturity at two or three of age. Young males exhibit subtle color differences from females but can best be distinguished by their enlarged femoral pores.
During the last few years there has been an emphasis on treating imported lizards for protozoan, nematode and other parasites which appears to be increasing survivability. There is some controversy among herpetoculturists as to whether parasite treatment for Uromastyx and other herbivorous lizards is more beneficial than harmful. This disagreement stems from research showing that microbes and nematodes are important for the digestion of plant material in iguanas and Egyptian spiny-tailed lizards (Foley, et al 1992, Iverson 1982). Chemicals used to treat harmful protozoans and nematodes also kill beneficial ones, therefore possibly adversely affecting the host lizard. More research is needed to clarify this situation so we can ensure greater survival of spiny-tailed lizards in captivity. In the meantime, it is best to work with a veterinarian who has extensive experience with reptiles.
Since the ornate spiny-tailed lizards can be difficult to keep alive for the first few months, you must choose the healthiest animal available. Look for animals that are alert and active. Pick the lizard up and look at the bottom of the tail where it joins the hind legs. The base of the tail should be robust. This characteristic does not guarantee health, but it is an indicator of an animal that is in good condition.
During August and September, hatchling ornate spiny-tailed lizards may be available. Since this species apparently has not been bred in captivity, these animals are either wild caught or hatched from eggs deposited by wild caught gravid females. Since young animals adapt more readily to captivity, they are your best investment.
The substrate can be paper, soil, sand or another suitable material. The substrate should be kept dry because in their native habitat it rains only one or two inches per year.
Artificial burrows allow the animal to feel secure in its new habitat. Snake hide boxes, upside down plastic plant saucers with holes cut in them, or hollow concrete construction blocks make good burrows.
Temperature should be provided by overhead spotlights so the lizards can bask as they do in the wild. The wattage of the bulb depends upon the size of the cage. Large cages (e.g., 2 feet by 4 feet) can be heated with a 125 watt heat lamp placed 12 inches above the substrate. Temperatures below the light will exceed 130 F but the other end of the cage should not rise above 90 F. This temperature gradient allows the lizard to seek its preferred temperature. Night time temperatures can drop into the high 60s F or low 70s F to emulate natural condition.
The natural sun produces many different wavelengths of light. Research indicates that some of these wavelengths, such as UVA and UVB, are important for the physical and psychological health of lizards. Full spectrum florescent lights can help approximate natural conditions, however there is no definitive research indicating that these lights are beneficial to captives. Even though the jury is still out, it is better to be safe than sorry, therefore full spectrum bulbs should be part of the cage set up. Dual bulb fixtures should contain both a full-spectrum bulb and a black light to help maximize the amount of UVA and UVB light available. The bulbs should be placed no more than 12 to 18 inches above the cage, with no glass or plastic between them and the lizard. If you can keep the animals outside, even if for only part of the year, you will ensure that they receive the benefits of full spectrum natural sunlight.
Most lizards are territorial, so it is best to keep males separate. Several females can be kept with a male but signs of stress, such a reduced activity or weight loss, should be watched for and if observed the stressed animal should be separated from the others.
Ornate spiny-tailed lizards will readily accept insects, although individuals exhibit varying preferences. Crickets, mealworms, superworms, wax worms and other insects can be offered. The crickets and superworms should be fed the same vegetables just described to ensure that their guts contain good nutrition which will then be transferred to the lizard.
Current research indicates that other herbivorous lizards such as iguanas do not consume much animal protein in the wild. Captive iguanas fed large amounts of animal protein can develop gout (Mader, 1995). Since there is no research on the natural diet of ornate spiny-tailed lizards caution should be exercised when feeding insects. The best bet is to feed insects only once or twice a week.
Ornate spiny-tailed lizards receive most of their water from the plants they consume, however they will drink from water bowls. Water can be continuously provided but make sure that it will not spill over and raise the cage's humidity.
Successful breeding efforts for both the North African spiny-tailed lizard and Egyptian spiny-tailed lizard have included a winter cooling period. The animals are cooled to 68 F in late November or December and kept at that temperature until late January or mid-February. In the wild, the North African spiny-tailed lizard does not hibernate all winter but emerges when temperatures are favorable (Vernet et al 1988), therefore a small wattage spot light is placed in the cage so the lizards can bask if they emerge from their retreat. This technique should also be used with ornate spiny-tailed lizards.
During the breeding season, which probably occurs in March or April, females can become aggressive (Richard Fife, personal communication) towards the male or other females. Animals should be closely observed during this period and separated if either animals appears injured or stressed. An egg laying site such as a small box containing moist sand or vermiculite must be placed in the cage. The eggs should be removed from the nest box and placed in an incubator.
There is much to learn about the ornate spiny-tailed lizard, however proper attention to temperature and a well balanced diet will help ensure that these animals adjust to captivity. Hopefully herpetoculturists will produce captive born young in the near future and make them available to others who want to work with this species.
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This document appeared in a different form in the July 1995 issue of REPTILES.
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