Green Tree Monitor
(Varanus prasinus)
Habitat: Tropical Rainforest    Diet: Carnivorous, primarily insects    Adult Size: 28-39 inches    Lifespan: 15 years or more with proper care   
Native To: Papua New Guinea and nearby islands
 

Did You Know:

  • The Green Tree Monitor is one of the few monitor lizards that is brightly colored.

  • A superb climber, the Green Tree Monitor has a monkey-like prehensile tail that it
    can wrap around the branches of trees. Special scales on its feet and long toes also
    contribute to its climbing ability.

  • Like a snake, this lizard will flick its tongue out to sense its surroundings.

The material below is a general guideline, and is not intended to serve as your sole source of pet care information. Visit a veterinarian trained in caring for reptiles and consult a broad range of literature to ensure that your pet receives adequate care.
 

What You Should Know About The Green Tree Monitor

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.
Lighting:
UVB Lighting Required: 		A Green Tree Monitor should be provided with 12 hours
a day of full spectrum lighting exposure. This will allow the lizard to synthesize calcium, and protect against metabolic bone disorder. Specialized reptile lighting should be used,
instead of plant or aquarium lighting, to provide these essential ultra violet rays. Fluorescent lamps producing UVB rays should be replaced every six months. Glass
blocks out UVB light, so overhead light sources should be kept behind a wire mesh cover, not a glass or acrylic tank top. A fluorescent light source should be within 12 inches of the animal. Important - see the Note About Day/Night Light Cycles and Heating below.

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 80º's in the cooling area to 115-120º Fahrenheit in the basking area. Temperature should be slightly lower at night but never below the low 80º'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. Important - see the Note About Day/Night Light Cycles and Heating below.

Note About Day/Night Light Cycles and Heating:

All reptiles, including this pet, must have distinct day and night periods in their enclosure to maintain their biological rhythms. (See the lighting entry above for the specific length of this animal’s day/night cycle.) The day period must be light; and night must be dark. A timer should be used to set day/night periods. If a heat source is required to maintain correct nighttime temperatures, use heat mats or strips mounted below or on the side of the tank, infrared heat lamps, ceramic heat emitters, or a combination of these products. This will allow the enclosure to be heated while remaining dark. Follow directions carefully with all products. If ceramic heat emitters are used always choose fixtures with porcelain or ceramic sockets and to protect against fires do not place them by dry wood or flammable fabrics. Ceramic heat emitters must be kept out of the reach of children and all pets, including dogs and cats.

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 with fresh chlorine-free water 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 chlorine-free water should always be provided. It's a good idea to mist a Green Tree Monitor before offering it food.
A NOTE ABOUT WATER: All water given to this pet for drinking, as well as water used for misting, soaking or bathing must be 100% free of chlorine and heavy metals. (Not all home water filtration systems remove 100% of the chlorine and heavy metals from tap water, so check your system's specifications before using it to filter water for your pet.) We recommend that you use unflavored bottled drinking water or bottled natural spring water and never untreated tap water. If tap water is used, you should treat it with a dechlorinating treatment. Do not use distilled water, which can cause severe medical problems, since it lacks minerals that are essential to important body functions.
Diet:
Frequent Feedings: 		Since Green Tree Monitors are very active lizards; they need to be fed frequently. They should never go more than a day without food. Small frequent meals are much better than infrequent large ones. The Green Tree Monitor's diet consists
mainly of gut-loaded insects that are dusted with a supplement, such as commercially raised crickets, cockroaches, and mealworms. However, they will also take feeder mice. Variety is important to this lizard's diet. Per-day portion size should be 12-24 crickets (or appropriate size feeder mouse) for adults, and 6-12 crickets for juveniles. Important -- It is necessary to provide calcium and vitamin supplements as part of the diet. Please read the supplement section below:
A Note About Gut Loading Feeding crickets a nutritious diet will pass on vital nutrients to your reptile. When reptiles eat these insects they are able to absorb the nutrients. This is why it is important to gut load crickets at least 48 hours before offering them to a reptile. Commercial cricket foods provide a convenient way to gut load crickets. (Always follow manufacturer’s directions.) Crickets should also be provided with water, preferably in the form of oranges or a commercial water gel product designed specifically to hydrate feeder insects. Putting a shallow dish of water in the cricket holding tank will result in insects drowning and promote the spread of bacteria.

You can also create your own gut-loading formula. Our vet recommends a mix of ground up dog food, cereal and fresh greens with oranges or a commercial gel for water.
Supplements: Dust insects with calcium supplement and vitamin supplements. As a rule, a growing juvenile's food should be dusted more often than an adult's. Follow product label directions when applying supplements, and avoid over-supplementing food. The following is a possible supplementing schedule for this reptile. Our veterinarian recommends dusting insects with a plain calcium supplement every time they are offered to the pet. (Avoid using a calcium supplement with added phosphorous, unless specifically directed by your veterinarian, since this can promote kidney disease.) Our veterinarian also recommends dusting insects with a D3 supplement once a week and a vitamin supplement two times a month. This is only one recommendation, consult your veterinarian for specific directions on supplementing your pet’s food, since there are many variables that go into determining the best supplementing regimen for a given animal.

How to Handle A Green Tree Monitor:
This lizard should be handled only when absolutely necessary. Approach from the side, speaking to the lizard in a soothing voice. Grab firmly around the neck with one hand and around the waist with the other and pull it into your body under your elbow to restrain the legs and tail. Two people may be necessary, and you may want to wrap the lizard in a towel. Always wash your hands before and after handling a lizard.


Look Out For This:
Green Tree Monitors are delicate lizards with exacting care demands in captivity. This lizard is not an appropriate pet for anyone but the most advanced reptile keeper. Handling causes stress in these lizards, so it should be kept to a minimum.


Recommended Green Tree Monitor Supplies:

  • An enclosure that provides plenty of vertical room for climbing

  • UVB and UVA emitting light

  • Heating element to maintain enclosure temperatures

  • Three thermometers, so temperature can be monitored at both ends of the enclosure and in the basking area

  • Appropriate substrate

  • Shallow water bowl

  • Spray bottle

  • Climbing and basking branches

  • Hiding area

  • Calcium and vitamin supplement

  • Hygrometer to measure humidity levels

  • Thermostat and rheostat to regulate heat