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CARE SHEET FOR THE GENUS UROMASTYX
Randall L. Gray
These interesting lizards have become more popular during the last few
years. Unfortunately there is little known about the genus. The following
guidelines will help maintain these animals in captivity. Hopefully as
more people work with the genus success stories will become more numerous.
The only way to ensure better husbandry for these unusual lizard is for
all herpetoculturists to share their information.
TAXONOMY AND DISTRIBUTION
There are approximately 13 species in the genus Uromastyx. These lizards
are adapted to arid regions and are found from northwestern India throughout
southwestern Asia and the Arabian Peninsula to the Sahara of Africa (Moody
1987). Members of this genus are referred to as dab lizards or spiny tailed
lizards. There are six species (U. aegyptius, 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 aegyptius 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
aegyptius 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.
Behavior differs between species and even individuals within the same species.
Some, Uromastyx acanthinurus and Uromastyx aegyptius, can
be very shy, often retreating to a hide spot when someone approaches the
cage. Others, Uromastyx ornatus, will often be tame. Individuals
differ in their behaviors and you can find exceptions to the above generalizations.
Large numbers of Uromastyx aegyptius and Uromastyx ornatus
have been imported into the country during the last few years. The US Fish
and Wildlife Service estimated that 7,000 members of the genus were brought
in 1994. 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 aegyptius is hardier and with proper treatment adapts
to captivity. Uromastyx acanthinurus have not been imported from
Morocco for several years, however, a few animals occasionally come from
Europe and a only two private breeders are known to occasionally produce
captive born animals. There is probably less than 100 animals in the United
States. This species adjusts well to captivity even if reproductive success
is not common.
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 and 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.
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.
Research with green iguanas indicates that submissive males in sight or
smell of a dominant male have slower growth rates. Uromastyx males
should be housed separately. Some herpetoculturists even house females
individually and only introduce them to males during the breeding season
(Matt Moyle, personal communication). 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 set-ups. Cages can consist of glass aquariums,
metal stock tanks, or wooden boxes. Sand, dirt and newspaper are often
used for substrate. 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 and should 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 inches in the ground and standing 24 inches 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.
These lizards are adapted to hot desert conditions. The cage should have
a daytime hot basking spot where the temperature exceeds 120 F, 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. Under tank
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 approximately the way diurnal lizards obtain their heat naturally.
Night time temperatures should be less that the daytime highs. Temperatures
should be allowed to drop into the mid 60's F.
Ultraviolet light is believed to be important for most lizards. Unfiltered
sunlight (i.e. not through glass) is the best sources of ultraviolet light
and lizards should always be exposed to sun whenever possible. There are
several full spectrum fluorescent light bulbs on the market. Most claim
that they duplicate the sun's light spectrum, however it is unlikely that
any can achieve the intensity of ultraviolet light emitted by the sun.
There is no scientific research supporting the assumption that these bulbs
are beneficial, however there use is recommended since there is some antidotal
evidence that they provide psychological benefits to the lizards. The new
ZOOMED full spectrum bulb appears to have the highest UVA and UVB of any
of the full spectrum bulbs on the market, therefore it is recommended.
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
aegyptius 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 infrequently in a bowl. The bowl
should not be left for long periods in the cage or it can raise the humidity
to possibly unacceptable levels. Baby Uromastyx ornatus will drink
water sprayed on the side of the cage.
Uromastyx are omnivorous which means they consume both animal and
plant materials. Since there is no data about the specific nutritional
requirements of this genus a large variety of food items should be offered.
Young animals more readily accept insects such as wax worms, crickets,
and super meal worms, which should be offered three or four times per week.
The following vegetables should 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 other 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. Some of the commercial iguana chows can
also be mixed in with the salad to ensure better nutrition. There are some
indications that nutritional needs are not easily met for this genus. Several
herpetoculturists who are raising young Uromastyx aegyptius and
Uromastyx acanthinurus report slow growth rates. For example, I
obtained two captive born Uromastyx aegyptius that were three inches
long. Within eight months one animal was five inches long and the other
11 inches and much bulkier. The only difference in husbandry was that the
larger animal would eat insects and smaller one would not. I have also
observed slow growth in captive born Uromastyx acanthinurus.
Several zoos (Christie 1993, Thatcher 1990, Wheeler 1988) and private breeders
have successfully bred Uromastyx aegyptius 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.
Christie, Bill. 1993. The Egyptian spiny-tailed lizard at the Indianapolis
Moody, Scott. 1987. A preliminary cladistic study of the lizard genus
(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
lizard, Uromastyx acanthinurus.
British Herpetological Society Bulletin. 40:9-13
Wheeler, Scott. 1988. Husbandry of the spiny-tailed agama (Uromastyx
at the Oklahoma City Zoo. In Proceedings
of the 11th International Herpetological
Symposium on Captive Propagation
and Husbandry. (ed.) Michael J. Uricheck.