Varanus exanthematicus is listed as a threatened species (Quality Design 1998). In Africa it is persecuted for its skin and as a source of food by the natives. The animal is also exported in great numbers for the pet trade.
US Federal List: threatened
IUCN Red List of Threatened Species: least concern
Varanus exanthematicus is very common in the United States in pet store. It is also used in many lizard skin leather products.
In the wild the diet of adult V. exanthematicus consists of small mammals, birds, snakes, toads, lizards, and eggs (Steele 1996). Other source contradict this finding and say that there is no proof that V. exanthematicus eat any type of vertebrate (Bennett 1999). Many adults also consume large quantities of snails. Full grown V. exanthematicus have teeth that are quite blunt to help them crack and eat snails. The jaw has evolved to put maximum leverage at the back of the jaw to crush snail shells (Steele 1996). Adults will also eat carrion if they come across it. Juvenile V. exanthematicus are mainly insectivores because they lack the teeth to eat snails. Savannah monitors have evolved a way to eat poisonous millipedes. The lizard will rub its chin on the millipede for up to fifteen minutes before eating it. It is believed to do this to some how avoid the distasteful fluid that the millipede excretes in it's defense (Steele 1996).
Varanus exanthematicus feeding habits revolve around the weather. They use a feast and fast system. They feast during the wet season when food is plentiful and easy to find. During the dry season they live off the fat reserves they built up over the wet season. The wet season last for about eight months. During this time V. exanthematicus can consume up to one tenth of its own body weight in a single day (Steele 1996).
Varanus exanthematicus, or the savannah monitor, is found throughout most of Africa south of the Sahara (Steel 1996). It is found in west and central parts of Africa and southward toward Zaire (Rogner 1997).
Biogeographic Regions: ethiopian (Native )
Varanus exanthematicus occupies a variety of habitats in Africa. Its preferred habitat is the savannah, but they have adapted to other habitats as well. The lizards have adapted to habitats such as rocky dessert type areas, open forests and woodlands. They are not found in the rainforest or deserts (Steele 1996).
Terrestrial Biomes: savanna or grassland ; forest
Average lifespan
Status: captivity: 12.7 years.
V. exanthematicus has five subspecies (Steele 1996). This is why the measurements and descriptions vary in much of the literature. Varanus exanthematicus is a thick, stockily proportioned monitor. It has wide head, short neck and tail. The tail tapers and has a double toothed crest. Savannah monitors can reach lengths of up to 1.5 meters (Steele 1997). Other sources say they can reach sizes of up to 2 meters (Rogner 1997). Small sub-equal scales cover the cranial region of the animal. The abdominal scale rows number between 60 and 110. The caudal scales of V. exanthematicus are keeled.
Varanus exanthematicus is gray to brown in color. There are rows of circular, dark edged yellow spots across the animal's back. The tail has alternating brown and yellowish rings. The under body and inside of the limbs is a yellowish color. The tongue of V. exanthematicus is snake-like and blue in color (Steele 1996).
Range mass: 1 to 70 kg.
Other Physical Features: heterothermic
The breeding season for V. exanthematicus is the same as the feasting period. They feast and breed during the wet season (Steele 1996). When a male finds a mate he will follow her around relentlessly, occasionally biting her on the neck and scratching her neck and legs with his claws. Eventually the female allows the two to mate.
The female will dig a nest herself and lay 20 to 50 eggs (Rogner 1997). Other sources say that the female digs nests that are 15-30 cm deep and only lays up to 15 eggs (Bennett 1999). Some females will lay their eggs in termite mounds. The eggs of V. exanthematicus have an unusually high hatch rate of 100 % (Bennett). Incubation of the eggs takes five to six months and the eggs hatch out in March (Rogner 1997). In the sandy farmlands of Ghana it has been reported that up to 55 babies can be found in an area of 150,000m2 during August and September. The juveniles grow the quickest during their first two months (Bennett 1999).
The savannah monitor (Varanus exanthematicus) is a medium-sized species of monitor lizard native to Africa. The species is known as Bosc's monitor in Europe, since French scientist Louis Bosc first described the species.[2] It belongs to the subgenus Polydaedalus.
The specific name exanthematicus is derived from the Greek word exanthem /ɛkˈsænθɪm/, meaning an eruption or blister of the skin.[3] French botanist and zoologist Louis Augustin Guillaume Bosc[4] originally described this lizard as Lacerta exanthematica in reference to the large oval scales on the back of its neck.[2]
The species was formerly known as Lacerta exanthematicus.[5]
Savannah monitors are stoutly built, with relatively short limbs and toes, and skulls and dentition adapted to feed on hard-shelled prey. They are robust creatures, with powerful limbs for digging, powerful jaws and blunt, peglike teeth. Maximum size is rarely more than 100 cm. The skin coloration pattern varies according to the local habitat substrate. The body scales are large, usually less than 100 scales around midbody, a partly laterally compressed tail with a double dorsal ridge and nostrils equidistant from the eyes and the tip of the snout.[6]
The savannah monitor is often confused with the white-throat monitor (Varanus albigularis), which can grow to lengths of 5–6 ft. While similar in overall appearance, this species possesses significant morphological and ecological differences and is recognized as a very distinct species.
Their diet is much more restricted than that of other African monitor lizards, consisting mainly of snails, crabs, scorpions, millipedes, centipedes, orthopterans, mantids, hymenopterans, lepidopterans, beetles and other invertebrates, as well as frogs.[7][8] Information about the diet of savannah monitors in the wild has been recorded in Senegal and Ghana.[9][10][11] It feeds almost exclusively on arthropods and molluscs. In Senegal, Julus millipedes were the most common prey of adults; in Ghana, small crickets formed the bulk of the diet of animals less than 2 months old; orthopterans (especially Brachytrupes), scorpions and amphibians were the most common prey of animals 6–7 months old. Many adults also consume large quantities of snails. Full grown V. exanthematicus have teeth that are quite blunt to help them crack and eat snails. The jaw has evolved to put maximum leverage at the back of the jaw to crush snail shells. Adults will also eat carrion if they come across it.[12] Wild savannah monitors are also known to occasionally eat lizard eggs (such as those of agamids and their own kind).[13][14]
Females dig a deep hole in the substrate, in which up to 40 or more eggs are laid, which hatch after about 156–160 days. Hatchlings start feeding a few days after the yolk sac has been absorbed, which may take 12 days or more after hatching.[15]
The savannah monitor is the most common monitor lizard species available in the pet trade, accounting for almost half (48.0552%) of the entire international trade in live monitor lizards. [16] Despite its prevalence in global pet trade, successful captive reproduction is very rare, and a high mortality rate is associated with the species. [17] Adult specimens frequently become unwanted pets and are reported as being the most common monitor lizards by animal rescue agencies. The skins are traded within the international leather trade and originate mainly from Chad, Mali and Sudan.
Its range extends throughout sub-Saharan Africa from Senegal east to Sudan and south almost to the Congo River and Rift Valley, where they are replaced by V. albigularis.[10] V. exanthematicus is primarily a ground-dwelling species that shelters in burrows, although it is sometimes found in bushes or low trees.[6] In the coastal plain of Ghana, V. exanthematicus juveniles are often associated with the burrows of the giant cricket Brachytrupes.[18]
V. exanthematicus is listed as least concern by IUCN.[1] The species is hunted for its leather and meat, and for the international pet trade. The trade in wild collected savannah monitors is not of a global conservation concern, due to the vast range of the species; in addition to the collection for the pet trade often occurring over a relatively small area.[19] An average of 30,574 live specimens were imported into the US each year, between 2000 and 2009; total imports of live specimens into the US between 2000 and 2010 was 325,480 animals. During the same period, 1,037 skins, shoes, and products of the species were imported into the US. Trade in live animals comes mainly from Ghana (235,903 animals exported between 2000 and 2010), Togo (188,110 animals exported between 2000 and 2010), and Benin (72,964 animals exported between 2000 and 2010). During the same period, total worldwide declared exports of skins and products of the species totalled 37,506.[20] However, substantial undeclared trade in the species occurs from Sudan, Nigeria, and elsewhere.[1] Within several West African nations, roadside diners and food stands specialize in “monitor stew”, a hot simmered dish of local vegetables and savannah monitor; it is unclear whether the cooked lizards are hunted or bred specifically for human consumption, or at what rate they are being killed for this purpose.[21]
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{{cite book}}: |author= has generic name (help) The savannah monitor (Varanus exanthematicus) is a medium-sized species of monitor lizard native to Africa. The species is known as Bosc's monitor in Europe, since French scientist Louis Bosc first described the species. It belongs to the subgenus Polydaedalus.
