Australian Wildlife

  Ridge-tailed Monitor (Varanus acanthurus)

Ridge-tailed Monitor | Varanus acanthurus photo
Ridge-tailed Monitor

Image by Factumquintus - GNU Free Documentation License.    (view image details)

Ridge-tailed Monitor | Varanus acanthurus photo
Ridge-tailed Monitor

Image by Haplochromis - Some rights reserved.    (view image details)


The Ridge-tailed Monitor is an attractively marked lizard with light brown ocelli markings (round spots with a darker centre) on the upper side. The head is patterned with dark brown and cream stripes. The tail has rows of rigid sharp spines forming ridges along its length. It has a forked tongue like a snake that is constantly flicked in and out detecting different scents. They have strong claws and jaws.

Other Names
Spiny Tailed Monitor

small to medium monitor growing up to 70cm total length

rocky regions in arid country. It hides in rock crevices when threatened, using the spines on its tail to wedge itself in and making it extremely difficult for a predator to dislodge. It is mainly terrestrial but sometimes lives inside tree hollows.

small lizards, mainly geckos and skinks and insects. When attacking prey the tail is used like a whip

lays between 5 to 8 eggs in a small chamber at the end of a tunnel dug into sandy soil

The Ridge-tailed Monitor is found in the northern half of Western Australia, Northern Territory and western Queensland. Also present on some of the associated islands.

distribution map showing range of Varanus acanthurus in Australia

Map is from Atlas of Living Australia website at https://biocache.ala.org.au licensed under Creative Commons Attribution 3.0 Australia License

Order:Squamata (Sauria)
Common Name:Ridge-tailed Monitor

Relatives in same Genus
  Stripe-tailed Monitor (V. caudolineatus)
  Perentie (V. giganteus)
  Pygmy Mulga Monitor (V. gilleni)
  Kimberley Rock Monitor (V. glauerti)
  Gould's Monitor (V. gouldii)
  Mangrove Monitor (V. indicus)
  Pygmy Rock Monitor (V. kingorum)
  Mertens' Water Monitor (V. mertensi)
  Yellow Spotted Monitor (V. panoptes)
  Emerald Tree Monitor (V. prasinus)
  Heath Monitor (V. rosenbergii)
  Spencer's Monitor (V. spenceri)
  Storr's Monitor (V. storri)
  Spotted Tree Monitor (V. timorensis)
  Black-headed Monitor (V. tristis)
  Lace Monitor / Goanna (V. varius)