Reptiles Database

Order Squamata
Suborder Anguinomorpha
Superfamily Varanoidea

Family Varanidae (Monitor Lizards)


Varanus indicus.
© Peter Uetz

Appearance: All living varanids share a small head, long neck, sturdy body and limbs, and long, powerful tail.

Distribution: Old World tropics: Africa, Asia, Australia.

Habitat: Arid or desert areas to tropical rain forest.

Size: 23 cm (pygmy goanna, Varanus brevicauda) to 3.1 m (Komodo dragon ,V. komodensis) total length (however, the tail makes up most of the animal). Fossil monitors are estimated to have been 6 meters long!

Reproduction: Oviparous. Their courtship is often preceded by rirualized male combat, that is, an upright grappling/dancing posture.

Food: All varanids are carnivores, although the Philippine butaans (V. olivaceus) seasonally eat fruit. The smaller species prey mainly on insects, small reptiles, and amphibians. With increasing body sizes, prey preference shifts increasingly to larger vertebrates, including mammals.

Behaviour: Most species are terrestrial-arboreal predators, searching for prey in trees as well as on the ground. Some species (V. indicus, V. niloticus) regularly forage near water and occasionally in water. Varanus mertensi feeds and hides in water.

List of genera:

Phylogenetic relationships among varanid species (from FULLER et al. 1998)

Relationships among the 23 varanoid taxa examined, obtained from 12S rRNA sequence analysis by a maximum-parsimony method. A more detailed analysis was published by AST (2001). See her phylogenetic tree for details.

References:

Ast, Jennifer C. (2001)
Mitochondrial DNA Evidence and Evolution in Varanoidea (Squamata).
Cladistics 17(3):211-226 [erratum in 18 (1):125]

BENNETT, D. (1997)
Monitor Lizards - Natural History, Biology and Husbandry.
Chimaira, Frankfurt/M., 352 pp.

Brian Green, Dennis Goanna King (1999)
Monitors : The Biology of Varanid Lizards, 2nd ed.
Krieger Publishing Company, Malabar.

Fitch, A.J.; Goodman, A.E.; Donnellan, S.C. 2006
A molecular phylogeny of the Australian monitor lizards (Squamata: Varanidae) inferred from mitochondrial DNA sequences.
Australian Journal of Zoology 54(4):253-269.

Fuller, Susan; Peter Baverstock and Dennis King (1998)
Biogeographic Origins of Goannas (Varanidae): A Molecular Perspective.
MOLECULAR PHYLOGENETICS AND EVOLUTION 9 (2): 294-307

King, Dennis;King, Max;Baverstock, Peter (1991)
A new phylogeny of the Varanidae.
Mertensiella 2 : 211-219

Mertens, Robert (1942)
Die Familie der Warane (Varanidae). (3 parts).
Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft 462 : 391 pp.

Zug,G.R. (1993)
Herpetology
Academic Press San Diego, London, XV + 527 pp.

Online Information: