North African spiny-tailed lizards attain a maximum total body length of 40 to 43 cm and an adult mass of 450 g. These lizards have a dorsally flattened body and the tail, as the name would suggest, is large and covered with ringed spines. Individuals may exhibit wide variation in color as the scales of adults are at times either a mottled red, orange, green, or yellow, though the basic color is gray. Juvenile individuals are almost always gray and brown. Scale colors reach their greatest intensity at about four years of age, which coincides with reaching sexual maturity. The colors also change with stress level and body temperature.
Basal metabolic rate does not seem to have been researched directly for this species. However, metabolic rate has been researched in the closely related Uromastyx microlepsis. At the optimum temperature of (104 degrees Fahrenheit) and for large lizards with an average body mass, the average basal metabolic rate is approximately 41 mL/hour of oxygen.
Many Uromastyx species can be very easily confused. They all have the same blunt head and large, spiny tails. Many also might have similar intricate patterns. Seemingly the best way to tell species apart is to observe the color patterns on the lizards. usually has a bright background color such as red, orange, yellow, or green. This is then overlaid with a series of elongated, curling dark brown or gray spots. These spots become much denser on the neck of this species. Since most other species are not as brightly colored as , the colors and the patterns should allow identification. This is made difficult by sometimes having a basic gray or brown color, so caution is advisable. ("Uromastyx acanthinura", 2006; Bartlett, 2003; Highfield and Slimani, 2010)
In some lizards, the sex of offspring is dependent on incubation temperatures, but breeders of Uromastyx have reportedly produced both sexes at a range of temperatures so it is possible that sex is genetically determined in this species. (Bartlett, 2003)
Post-oviposition parental investment in North African spiny-tailed lizards consists of the attendance and guarding of the nest by the female. Males have no parental investment beyond fertilizing the eggs. The eggs are laid in the female's burrow, and the increased aggression the females exhibit around the breeding season is attributed to guarding behavior. The female guards the eggs at least for the 8 to 12 weeks it takes for the eggs to hatch. However, it is not clear whether or not the female remains to guard the neonates during their post-hatching period in the burrow. Since ("Uromastyx acanthinura", 2006; Bartlett, 2003; Gray, 2001; Highfield and Slimani, 2010)is a solitary and territorial species, young lizards are very likely completely independent upon leaving the burrow and must establish their own territories. It is also likely that the mother retains her own burrow.
There is little information regarding the lifespan of North African spiny-tailed lizards. There is evidence that lizards in captivity have lived up to 20 years when caught in the wild. These captured individuals were sexually mature adults, thus it is reasonable to assume they would have been at least 4 or 5 years old when captured. ("Uromastyx acanthinura", 2006; Bartlett, 2003; Gray, 2001)
The presence of parasites has been recorded in this species. Therefore, parasitism and predation are likely two factors affecting life span. (Gray, 2001)
This species is often very aggressive against other members of its own species. Individuals fiercely defend territory against intruders. In captivity, even siblings hatched from the same clutch of eggs will attack one another if housed together for too long. In fights, this species tends to bite the sides of its opponents. This can leave white, colorless scar tissue in those areas. (Gray, 2001)
This species is highly territorial and solitary. The territory of each individual can extend from 10,000 to 50,000 meters squared. This species does live in discrete populations as well however. Populations can consist of anywhere from 10 to 100 individuals living in one square kilometer. The lizards are quite sedentary. They only ever move significantly when traveling from food plant to food plant, and usually stay within the bounds of their territory. This is thought to be behavior designed to avoid predation. ("Uromastyx acanthinura", 2006; Highfield and Slimani, 2010)
Little information exists on communication between individuals in this species. Courtship involves visual displays of head swinging and push-ups. Males also use secretions from their femoral and anal glands to mark their territories upon reaching sexual maturity. (Highfield and Slimani, 2010)
This species likely perceives its environment predominantly with sight, based on its reliance on visual cues in courtship. It may also use tactile cues in locating preferred soil types for burrowing. There is also evidence that at least some species of the Uromastyx genus use chemical cues to find mates and the food they prefer. Studies have shown individuals prefer tiles lacking visual cues for food but smeared with favorite food items. However, studies with this specific species would be necessary to confirm that this is the case for . (Bartlett, 2003; Cooper and Al-johany, 2002)
North African spiny tailed lizards are primarily herbivorous lizards. However, they also will consume ants (family Hymenoptera) and beetles (family Tenebrionidae). Young lizards are more willing to consume insects. Most of the desert plants it eats are highly fibrous. It is known that other Uromastyx species make use of microbial digestion and a complex digestive tract that maximizes surface area to absorb as much nutrients possible.
One of the primary food sources is plants of the genus Chenopodium which includes fat hens (Chenopodium album) and some types of spinach. They also commonly eat plants of the salt tolerant genus Atriplex. Since the soil in deserts tends to have a high salt content, many plants tend to also have high salt concentrations in their leaves. As a result this species has glands in its nostrils used for eliminating extra salt without eliminating water. (Foley, et al., 1992; Gray, 2001; Highfield and Slimani, 2010)
Specific predators for this species are not well known. In a closely related species, Uromastyx aegyptia, adults are often predated by raptors, wolves, and dogs. Juvenile Uromastyx aegyptia are more easily preyed upon and are often attacked by monitor lizards (genus Varanus), shrikes (Laniidae family), and snakes. ("Uromastyx acanthinura", 2006; Nemtzov, 2008)
Adults of this species will immediately hide in burrows when approached by a predator or curious human.builds burrows that can be upwards from 4 meters deep in which they hide as soon as a perceived threat approaches. The burrows can also have multiple entrances and exits that are used to confuse and escape predators. If attacked while in the burrow, these lizards use their powerful limbs to cling tightly to burrow walls to avoid being dragged out. If attacked outside of the burrow, they are not hesitant in using their large spiny tails to defend themselves.
Juveniles do not build burrows, but instead tend to reside under stones or other shallow shelters. If approached, their first strategy is to freeze in place. Only after a few moments have passed will they seek shelter. Juvenile lizards likely suffer higher mortality rates because of this behavior. ("Uromastyx acanthinura", 2006; Gray, 2001; Highfield and Slimani, 2010)
This species acts as prey to many birds, snakes, wolves, and monitor lizards and thus these supports local populations. Foleyella candezei has been found in the liver or under the skin of these lizards, especially in individuals living in Algeria. External parasites include various mites and ticks. Since is an herbivore, it may assist in spreading the seeds of the plants it eats. (Bartlett, 2003; Yildirimhan, et al., 2006)also acts as host to several types of internal parasites including roundworms, pinworms, tapeworms, and protozoan. The nematode species
The burrowing activities of this species may also impact its ecosystem. It has been confirmed for the related species U. aegyptia that other organisms may take up residence in its burrows such as insects and snakes. Since also engages in burrowing in areas that are populated by snakes and insects, the same benefit to other organisms can occur with the burrows of this species. Also, the soil in deserts is often high in salt. When burrows are dug deep underground, it can bring soil with lower salt content to the surface. This can benefit plants growing around the burrows that have lower salt tolerances. (Nemtzov, 2008)
One benefit these animals offer to humans is through the pet trade. Their bright colors make them a desirable pet species. Uromastyx species. Captive breeding has now reduced the market for wild-caught animals. ("Uromastyx acanthinura", 2006; Bartlett, 2003)has been traded internationally in the past and was at one time the highest traded
There is also exploitation of these lizards for food and medicine. Though they are listed as Near Threatened in the IUCN red list, local native people have likely eaten and used them for medicine for many years, so illegal trapping is unlikely to stop anytime soon. This species is also sold as souvenirs or live. Live specimens are apparently sold frequently by children along roadsides at only the equivalent of $1.75 to $4.70. Certain herbalists and traditional healers in the southern part of its range use this species in medicine. There do not seem to be any studies available indicating any true medicinal use of this lizard, so this use is most likely based on culture. There are also some native tribes that use the skin of this species for holding liquid, and it is apparently often used as a baby bottle. ("Uromastyx acanthinura", 2006; Highfield and Slimani, 2010)
There are no true negative effects on humans caused by this species.
The international trade of Uromastyx species in Appendix II. Successful trade regulation is difficult to enforce as many can be sold through underground markets. This species is often misidentified, therefore making regulation increasingly difficult.is currently regulated by CITIES and is listed with all other
Additional threats to this species includes agricultural grazing on plants thatcommonly eats which creates competition for resources. More important factors that threaten its survival tend to come from humans through the pet trade and trapping for food and medicine. Road mortality is of great concern as the heat-absorbing roads are an attractive basking spot for these lizards.
This species has not been evaluated by the IUCN. ("An assessment of the international trade in Spiny-Tailed Lizards Uromastyx with a focus on the role of the European Union", 2004; "Uromastyx acanthinura", 2006; Highfield and Slimani, 2010)
More studies of this and related species in the wild are needed to better define ecological niches and assist conservation efforts.
Megan Climans (author), Michigan State University, James Harding (editor), Michigan State University, Rachelle Sterling (editor), Special Projects.
living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.
uses smells or other chemicals to communicate
in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.
a substance used for the diagnosis, cure, mitigation, treatment, or prevention of disease
parental care is carried out by females
union of egg and spermatozoan
an animal that mainly eats leaves.
A substance that provides both nutrients and energy to a living thing.
Referring to a burrowing life-style or behavior, specialized for digging or burrowing.
an animal that mainly eats fruit
An animal that eats mainly plants or parts of plants.
having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.
the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
the area in which the animal is naturally found, the region in which it is endemic.
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
the business of buying and selling animals for people to keep in their homes as pets.
communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them
breeding is confined to a particular season
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
Living on the ground.
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
uses sight to communicate
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Yildirimhan, H., S. Goldberg, C. Bursey. 2006. Helminth Parasites of the Caucasian Agama, Laudakia caucasia, and the Roughtail Rock Agama, Laudakia stellio (Squamata: Agamidae), from Turkey. Comparitive Parasitology, 75/2: 257-262. Accessed December 09, 2010 at http://www.bioone.org/doi/abs/10.1654/4205.1.
Zari, T. 1991. The influence of body mass and temperature on the standard metabolic rate of the herbivorous desert lizard, Uromastyx Microlepsis. Journal of Thermal Biology, 16/3: 129-133.