The emerald tree monitor or green tree monitor, is a small to medium-sized arborealmonitor lizard. It is known for its unusual coloration, which consists of shades from green to turquoise, topped with dark, banding. This coloration helps camouflage it in its arboreal habitat. Its colour also makes the emerald tree monitor highly prized in both the pet trade and zoos alike.
Varanus prasinus was first described as Monitor viridis by John Edward Gray in 1831; however, Gray's original holotype was lost and the species was redescribed by Schlegel eight years later as V. prasinus using the found specimen. The generic nameVaranus is derived from the Arabic word waral, which translates to English as "monitor". Its specific name, prasinus, is Latin for the color green. Varanus prasinus is a member of the subgenus Euprepiosaurus. It is closely related to several other arboreal species; when combined, these are often referred to as the V. prasinusspecies group or species complex. In addition to V. prasinus, this species group, whose members are all allopatric, includes V. beccarii, V. boehmei, V. bogerti, V. keithhornei, V. kordensis, V. macraei, V. reisingeri and V. telenesetes.
Emerald tree monitors and their close relatives can be found in New Guinea as well as several adjacent islands, and the northern Torres Strait Islands. The green tree monitor is reported to thrive in lowland environments, including tropical evergreen forests, palm swamps and cocoa plantations.
Description
The emerald tree monitor is about long with a slender body that helps it support itself on narrow branches. It uses its prehensile tail and long claws to grip branches. Unlike other varanids, this monitor defends its tail rather than lashing with it for defense when threatened. The soles of the feet of the emerald tree monitor have enlarged scales which aid the lizard when climbing.
Ecology
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.
Diet
The emerald tree monitor's diet consists of large tree-dwelling arthropods, such as katydids, stick insects, cockroaches, beetles, centipedes, spiders and crabs, as well as birds and small mammals. Before swallowing stick insects, the lizards tear off the legs. Captive specimens tear off the limbs of rodents prior to eating them; as a result, they are capable of swallowing mammals of a considerable size: A 135-g lizard was documented as eating a 40-g rodent, almost one-third its size. Paleontologist and Temple University professor Michael Balsai has observed V. prasinus eating fruit in captivity as has herpetologist and author Robert G. Sprackland.
Reproduction
Clutches consist of up to five eggs, each weighing and measuring about. As many as three clutches are laid throughout the year; clutches have been laid by captives in January, March, April, November, and December. The female emerald tree monitor lays her eggs in arboreal termite nests. The eggs hatch between 160 and 190 days later, typically from June to November, after which the young eat the termites and the termite's eggs within minutes of hatching. Sexual maturity is reached in about one year.
