The Basics:

This is a very active, brilliantly colored lizard with a slender head and body that lives in tropical rainforests and palm swamps in its natural environment. It is arboreal, spending much of its time in trees and active during the day. Males may fight if kept in the same enclosure, but a male will usually get along with one or more females. This lizard is also sometimes called the Emerald Monitor. Like other monitor lizards it is an excellent hunter in nature, and will consume a variety of prey.

Enclosure:
A Lot Of Vertical Space :

Green Tree Monitors are active lizards that require a
relatively large amount of space. Their space requirements far exceed their size, and they will use every bit of space made available to them. In nature they are avid tree climbers,
so a vertically oriented enclosure is essential. It's also a good idea to affix cork or some other material that the lizard can climb on to the side of the enclosure. An enclosure
should measure at least 6-feet high, by 4-feet wide, by 2-feet deep -- but bigger is definitely better. Large air vents and top screening should not be used on the enclosure,
since they will make it too difficult to maintain the necessary 70-percent humidity level. Another alternative is to use a 75-gallon or larger vertically oriented aquarium for a
single Green Tree Monitor, and at least a 200-gallon tank for two or three of these lizards. Thick climbing branches (over 4-inches in diameter) arranged vertically and horizontally, as well as hiding places are critical elements of a Green Tree Monitor's enclosure.

Substrate:
Moisture-Retaining Material:

Since humidity is so important to the health of
this species, it is essential to select a substrate that retains moisture without promoting the growth of mold. Leaf litter types of substrates are good choices.

Temperature:
A Very Warm Basking Spot:

Even by lizard standards, the Green Tree Monitor
needs a hot basking spot. Temperatures in the enclosure should be in the low 80s in the cooling area to 120-130 degrees Fahrenheit in the basking area. Temperature should be slightly lower at night but never below the low 80's. Heat
lamps can be used to maintain the desired thermal gradient, while a lamp can heat the basking spot. Nighttime temperatures can be maintained by ceramic heat emitters, which do not produce light. Follow directions carefully with ceramic heat emitters, use fixtures with porcelain or ceramic sockets and do not place by dry wood or flammable fabrics to
protect against fires. Thermometers should be positioned in the warmer and cooler areas of the enclosure as well as in the basking spot. Enclosure temperatures should be monitored at branch level as well as ground level.

Humidity:
High Levels Are Essential:

Green Tree Monitors come from a tropical rainforest
environment, and this should be reflected in the humidity levels maintained in their enclosures. At no time should the humidity level in this lizard's enclosure be allowed to
drop below 70-percent. A hygrometer should be used to measure humidity levels. Frequent daily mistings will maintain humidity, plus provide droplets that will keep the Green Tree Monitor hydrated. Like many lizards, Green Tree Monitors often will refuse water from a bowl, and instead drink by taking droplets from leaves and other surfaces. However, a bowl of fresh water should always be provided. It's a good idea to mist a Green Tree Monitor before offering it food.

The following is a possible supplementing schedule for this reptile. Once a week, the lizard should be offered insects that have been dusted with a calcium/vitamin supplement. Hatchlings and ovulating females should be given dusted
insects twice weekly. However, this is only a general suggestion -- the best specific schedule may vary depending on the supplement products used and other factors. Please consult product package directions, outside literature and a veterinarian to determine the optimal supplementing program.