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, along with the Nile, the ornate and other monitors.
The specific name exanthematicus is derived from the Greek word exanthem , meaning an eruption or blister of the skin.French botanist and zoologist Louis Augustin Guillaume Bosc originally described this lizard as Lacerta exanthematica in reference to the large oval scales on the back of its neck.
Bosc's, or savannah, monitors are stoutly built, with relatively short limbs and toes, and skulls and dentition adapted to feed on hard-shelled prey. Maximum size is usually between 105 and 155 cm (3.5 to 5.0 ft) in length, although most specimens collected in the wild range from 60 to 76 cm (2 to 2.5 ft), with females being considerably smaller. 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.
Information about the diet of savannah monitors in the wild has been recorded in Senegal and Ghana. It feeds almost exclusively on arthropods and molluscs. In Senegal, Iulus millipedes were the most common prey of adults; in Ghana, small crickets formed the bulk of the diet of animals less than two months old; orthopterans (especially Brachytrupes), scorpions and amphibians were the most common prey of animals six to seven months old .
Varanus exanthematicus is a rather popular lizard pet in the trade. This is owing to their often advertised docile disposition.
Contrary to popular belief however, the savannah monitor fails to thrive in most captive situations, and thus is not ideal for beginner herpetoculturists. It is estimated that 90% of savannah monitor lizards do not survive their first year of captivity. Thousands of savannah monitors are exported from the grasslands of Ghana annually for the exotic pet trade. The species is commonly "farmed" or captured from its natural environment. As a result, the species suffers widely from parasite infections, stress and injuries during shipment. It is estimated that less than 0.003% of V. exanthematicus exported into the United States successfully reproduced in captivity, thus the majority - if not all - savannah monitors sold into the exotic pet trade are wild caught. The United States is by far the largest importer of the savannah monitor lizard.
Furthermore, Varanus exanthematicus is considered to be a very misunderstood species. Proper care has yet to be established, but certain conditions are more adequate than others.
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.V. exanthematicus is primarily a ground-dwelling species that shelters in burrows, although it is sometimes found in bushes or low trees. In the coastal plain of Ghana, V. exanthematicus juveniles are often associated with the burrows of the giant cricket Brachytrupes.
Varanus exanthematicus is listed as Least Concern by IUCN. 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. 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. However, there is substantial undeclared trade in the species from Sudan, Nigeria and elsewhere