The Emerald Tree monitor (Varanus prasinus), or the Green Tree monitor, is a small-to-medium-sized arboreal monitor lizard. It is known for its unusual coloration, which consists of shades from green to turquoise, topped with dark, transverse dorsal banding. This coloration helps camouflage it in its arboreal habitat.[1] It also makes the Emerald Tree monitor highly coveted by private collectors and zoos alike.[2]


Varanus prasinus was first described as Monitor viridis by John Edward Gray in 1831; however, Gray's original holotype (RMNH 4812 in the National Natural History Museum in Leiden) was lost and the species was redescribed by Schlegel eight years later as V. prasinus using the found specimen.[3] The generic name Varanus is derived from the Arabic word waral (ورل), which translates to English as "monitor".[4] Its specific name, prasinus, is Latin for the color green.

V. prasinus is a member of the Euprepiosaurus subgenus. It is closely related to several other arboreal species and when combined these are often referred to as the V. prasinus species group. In addition to V. prasinus itself, this species group, whose members are all allopatric, includes V. beccarii (Aru Islands), V. boehmei (Waigeo Island), V. bogerti (D'Entrecasteaux Archipelago), V. keithhornei (Cape York Peninsula), V. kordensis (Biak Island), V. macraei (Batanta Island), V. reisingeri (Misool Island) and V. telenesetes (Rossel Island).[5][6]

Evolutionary developmentEdit

The evolutionary development of V. prasinus started with the Varanus genus, which originated in Asia about 40 million years ago and migrated to Australia and the Indonesian archipelago around 15 million years ago.[7]


Emerald tree monitors and their close relatives can be found in New Guinea, as well as several adjacent islands,[8] and the northern Torres Strait Islands.[9] The green tree monitor is reported to thrive in lowland environments including tropical evergreen forests, palm swamps and cocoa plantations.[9]



The emerald tree monitor is about Template:Convert long with a slender body that helps it support itself on narrow branches. It also has a prehensile tail and long claws that it uses to grip branches.[1][10][11] Unlike other Varanasi this monitor defends its tail rather than lashing with it for defense when threatened.[12] The soles of the feet of the emerald tree monitor have enlarged scales which aid the lizard when climbing.[11]


When threatened, the emerald tree monitor will flee through vegetation or bite if cornered. It is one of the few social monitors, living in small groups made up of a dominant male, several females, and a few other males and juveniles.[1]


The emerald tree monitor's diet consists of large tree dwelling insects such as katydids, stick insects, cockroaches, beetles, centipedes, spiders, crabs, birds, and small mammals. Before swallowing stick insects, the lizards tear off the legs.[8] Captive specimens tear off the limbs of rodents prior to eating them and as a result they are capable of swallowing mammals of a considerable size: A Template:Convert lizard was documented as eating a Template:Convert rodent, an animal almost one-third its size. Paleontologist and Biology Professor at Temple University, Michael Balsai has observed V. prasinus eating fruit(bananas) in captivity as has herpetologist and author, Robert G. Sprackland.[13][12]


Clutches consist of up to five eggs, each weighing Template:Convert and measuring about Template:Convert. As many as three clutches are laid throughout the year; captive clutches have been laid in January, March, April, November, and December. The female emerald tree monitor lays her eggs in arboreal termite nests.[11] The eggs hatch between 160–190 days, typically from June to November after which the young eat the termites and the termite's eggs within minutes of hatching.[11] Sexual maturity is reached in about two years.[4]


  1. 1.0 1.1 1.2 Template:Cite book
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  4. 4.0 4.1 Template:Cite book
  5. Jacobs, H. J. (2003). A further new emerald tree monitor lizard of the Varanus prasinus species group from Waigeo, West Irian (Squamata: Sauria: Varanidae). Salamandra 39(2): 65-74
  6. Ziegler, T., A. Schmitz, A. Koch and W. Böhme (2007). A review of the subgenus Euprepiosaurus of Varanus (Squamata: Varanidae): morphological and molecular phylogeny, distribution and zoogeography, with an identification key for the members of the V. indicus and the V. prasinus species groups. Zootaxa 1472: 1-28
  7. Ciofi, Claudio. The Komodo Dragon. Scientific American. Retrieved on 2006-12-21.
  8. 8.0 8.1 Template:Cite book
  9. 9.0 9.1 Template:Cite book
  10. Template:Cite book
  11. 11.0 11.1 11.2 11.3 Template:Cite book
  12. 12.0 12.1 Template:Cite book
  13. Template:Cite book

External linksEdit


Template:Use dmy datescs:Varan smaragdový de:Smaragdwaran nv:Tiníléítsoh dootłʼizhígíí es:Varanus prasinus fr:Varanus prasinus it:Varanus prasinus hu:Smaragdvaránusz nl:Smaragdvaraan ja:ミドリホソオオトカゲ no:Smaragdvaran pl:Waran szmaragdowy pt:Varanus prasinus ru:Зелёный варан sv:Smaragdvaran

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