The Uromastyx has only recently become a popular pet among reptile owners.  Little is known about these unusual lizards, which are found primarily in the arid regions from northwestern India through southwestern Asia, and the Arabian Peninsula to the African Sahara.  They are often called "dab lizards" or "spiny tailed lizards" because of their prehistoric-looking bushy spined tail.
 
There are six species (U. aegypticus, U. ornatus, U. ocellatus, U. acanthinurus, U. hardwicki, and U. benti) which are occasionally available in the United States.  The other seven species are seldom, if ever, imported.  Uromastyx aegypticus is the largest member of the genus, with individuals reaching 30 inches or more in total length and weighing several pounds.  The other species are usually under 14 inches in total length.
 
Coloration is variable between and within species.  Uromastyx aegypticus and Uromastyx hardwicki are usually dark to light brown.  Uromastyx acanthinurus can be yellow, green, bright orange or a combination of these colors.  Uromastyx ornatus are sexually dimorphic, with adult males being green or blue green with blotches of yellows and oranges.  Females have more subtle yellows, browns, and some orange.
 
General Characteristics
Behaviors differ between species, and even between individuals within the same species.  Some, such as Uromastyx acanthinurus and Uromastyx aegypticus, can be very shy, often retreating to a hide spot when someone approaches the cage.  Others, like the vivid Uromastyx ornatus, will often be tame.
 
Large numbers of Uromastyx aegypticus and Uromastyx ornatus have been imported into the country during the last few years.  The U.S. Fish and Wildlife Service estimated that 7,000 members of the genus were brought in during 1994 alone.  For unknown reasons, the death rate for Uromastyx ornatus is rumored to be as high as 80% during the first two months of captivity.  Uromastyx aegypticus is hardier, and with proper treatment adapts well to captivity.
 
Sexing
The presence of large femoral pores with waxy protuberance and hemipene bulges can often distinguish males; however, this is not obvious on all species.  Males tend to have broader heads, but this is often subtle or misleading.  Uromastyx ornatus are the easiest to sex, due to enlarged femoral pores on the males, plus adult males are more colorful than females.  Uromastyx acanthinurus can be extremely difficult to sex.  Probing does not work with Uromastyx acanthinurus, and may not be a useful tool for the genus.   An easier method to determining male from female is usually the color.  Uromastyx aegypticus and Uromastyx hardwicki (pictured above) males have a distinctly golden tint on their bellies, while the females are a subtler cream color.
 
Social Behavior
Most lizards are territorial, which means that the male and sometimes the female will defend an area from members of the same species, or even other species.  Often, in captivity, two male lizards will fight openly.  Even if aggression is not overt, the submissive male can be adversely affected.  Uromastyx males should always be housed separately.  Some herpetoculturists even house females individually, and only introduce them to males during the breeding season.
 
Caging
Each species of lizard is adapted to specific environmental conditions.  Knowledge about a species macro- and micro-habitat is critical in designing a cage setup; however, limited information is available regarding habitat type for each species of Uromastyx.  Generally the species are found in deserts, therefore they are best kept in desert setups.
 
Cages can consist of glass aquariums, metal stock tanks, or wooden boxes.  Sand, dirt, and newspaper are often used for substrate.  Utility mats can also be used; these are inexpensive and convenient, because they can be machine-washed when soiled.
 
Rocks or other objects should be placed in the cage to allow climbing and basking sites.  Any heavy objects, such as rocks, must be securely anchored, or the lizard will burrow underneath--causing the rock to fall and crush it.  Hide boxes provide the animals with a sense of security, and are especially important for gravid females.
 
Uromastyx can be kept outside during the summer, or all year in the southwestern United States where temperatures seldom drop below the mid 60's F.  A variety of outdoor caging types can be constructed, including a simple sheet metal ring sunk 12" in the ground, and standing 24" above ground (the height is adjusted depending upon the size of the animals).  Outdoor cages should be secured with a wire top to prevent predators (e.g. cats, birds, raccoons) from entering.
 
Temperature
These lizards are adapted to hot desert conditions.  The cage should have a daytime hot basking spot where the temperature exceeds 120ºF.   However, the lizard must be able to retreat to areas in the low 90's.  Incandescent spotlights can provide hot basking spots.  The wattage selected depends upon the size of the cage.  Thermometers should be placed at both ends of the cage, and monitored to ensure a proper temperature gradient.
 
Undertank heaters can be used to supplement heat; however, these are diurnal species, and regulate their body temperature by basking in the sun.  Spotlights more accurately approximate the way diurnal lizards obtain their heat naturally.
 
Nighttime temperatures should be less that the daytime highs.  Temperatures should be allowed to drop into the mid 60's F.
 
Lighting
Ultraviolet light is critical for most lizards.  Unfiltered sunlight (i.e. not filtered through glass or plastic) is the best sources of ultraviolet light, and lizards should always be exposed to the sun whenever possible.
 
There are several full-spectrum fluorescent light bulbs on the market.  The ZooMed Powersun bulb appears to have the highest UVA and UVB of any full-spectrum bulb on the market, and it also provides sufficient heat for Uromastyx; therefore it is highly recommended.
 
Water
Most desert species are adapted to live without free water.  Uromastyx ornatus comes from the Sinai Peninsula, where it rains less than 2 inches per year.  Many species obtain moisture from the food they consume.  There is evidence that some species, such as the Australian Moloch and North American horned lizards, collect morning dew on their scales, which is then channeled toward the mouth.
 
Many herpetoculturists soak their Uromastyx aegypticus in water, and claim that the animal swells as it absorbs water.  Whether the animal is actually filling up with water, or only filling it's body cavity with air, is unknown.  Considering that this is a desert species, soaking in water seems inconsistent with adaptations to arid conditions, and could lead to respiratory infections if the animal does not thoroughly dry after soaking.
 
Water can be provided in a bowl.  Baby Uromastyx will drink water sprayed on the side of the cage.
 
Food
Uromastyx are omnivorous, which means they consume both animal and plant materials.  Young animals will more readily accept insects such as crickets and superworms, which should be offered three or four times per week. The following vegetables should also be offered: kale, collard greens, mustard greens, sweet potatoes, carrots, peas, corn, and green peas.  In addition, dandelion greens, alfalfa, grass, and flowers can be added to the diet.  Beans such as split peas, lentils, navy beans, and others should also be provided.  Some of these beans can be sprouted prior to feeding.  Bird seed should also be mixed in with the salad.
 
A reptile vitamin containing calcium should be sprinkled on the salad, or sprayed on the lizard externally.
 
Reproduction
Several zoos and private breeders have successfully bred Uromastyx aegypticus and Uromastyx acanthinurus.  However, reproduction is not a regular occurrence.  All breeders provide a winter cool-down to stimulate reproduction.
 
Apparently Uromastyx take several years to reach sexual maturity.  As a comparison, North American chuckawallas, an ecological equivalent, take five to seven years to reach sexual maturity.  Some of the smaller Uromastyx may reach sexual maturity in two or three years.
 
Literature Cited:

	Christie, Bill. 1993. The Egyptian spiny-tailed lizard at the Indianapolis Zoo. Captive Breeding 1(3):20-25.
	Moody, Scott. 1987. A preliminary cladistic study of the lizard genus Uromastyx (Agamidae, sensulato), with a checklist and diagnostic key to the species. In Proceedings of the Fourth Ordinary General Meeting of the Societas Europaea Herpetologica; (eds) J.J. van Gelder, H. Strijbosch and P.J.M. Bergers.
	Thatcher, Terry. 1990. The reproduction in captivity of the North African spiny-tailed lizard, Uromastyx acanthinurus. British Herpetological Society Bulletin. 40:9-13
	Wheeler, Scott. 1988. Husbandry of the spiny-tailed agama (Uromastyx acanthinurus) at the Oklahoma City Zoo. In Proceedings of the 11th International Herpetologcial Symposium on Captive Propagation and Husbandry. (ed) Michael J. Uricheck.