Emerald Tree Monitor (Varanus prasinus)

Common Name: Emerald Tree Monitor
Scientific Name: Varanus prasinus
Source: CBID26
Adult Size: 75–100cm total length (including tail)
Native Range: New Guinea and surrounding islands, including parts of far north-eastern Australia

Enclosure: A minimum 120×60×120cm Viperia PVC vivarium for a single adult — this arboreal (tree-dwelling) species needs height above all else. Fill the enclosure with sturdy horizontal and diagonal branches at varying levels, add dense cork bark and live or artificial foliage for cover, and use a moisture-retaining substrate such as coco coir or bioactive soil at the base to help maintain humidity.
Heating: Basking spot 38–42°C; ambient air temperature 28–32°C; night-time drop to 22–24°C is acceptable.
Humidity: 70–90%. Achieve this through daily misting, a large water feature or fogger, and moisture-retaining substrate; ensure good ventilation to prevent stagnant, stale air while keeping humidity high.
UVB: A 7% UVB tube mounted at the top of the enclosure, positioned so the animal can bask 25–35cm from the lamp along its higher branches; replace the tube every 12 months even if it still appears to emit visible light.
Diet: Primarily insects — large crickets, locusts, Dubai roaches, and other invertebrates form the core of the diet. Small amounts of lean protein (e.g. pinky mice for adults, occasionally) can be offered sparingly. Juveniles should be fed daily; adults every 2–3 days. Dust insects with a calcium supplement on most feeds and a multivitamin supplement once a week.

ABOUT THIS SPECIES

The Emerald Tree Monitor is one of the most visually striking lizards in the hobby — its vivid green colouration serves as natural camouflage in the rainforest canopies of New Guinea, where it spends the vast majority of its life high above the forest floor. Unlike many monitors, it has a prehensile (gripping) tail that functions almost like a fifth limb, helping it navigate branches with remarkable agility.

These are active, intelligent monitors that reward experienced keepers with endlessly interesting behaviour, but they are not a beginner's lizard — they can be skittish and require precise environmental conditions to truly thrive. Keepers who invest time in building trust and maintaining a well-planted, humid enclosure will find them an exceptionally rewarding and beautiful species to work with.