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Green Tree Monitor Care Guide

The Green Tree monitor is a popular choice for a pet. This species is one of the smaller to medium-sized reptiles, growing only up to 3 feet long on average.

The care for this attractive and interesting species is not difficult. From enclosure set-up to feeding, you can have a manageable and fun time caring for this reptile in your own home. Read on to find out more.

Green Tree Monitor Facts

  • Experience level: Intermediate to Advanced
  • Family: Varanidae
  • Scientific name: Varanus prasinus
  • Average adult size: 3 feet or less than 1 meter on average
  • Lifespan: 15 years
  • Clutch Size:  3 to 7 eggs and multiple clutches on occasion, especially in captivity
  • Egg Incubation Period: 23 to 24 weeks
  • Food: large insects like crickets and cockroaches; small prey like geckos, frogs, birds,
  • Average Temperature: Between 25°C to 26°C
  • Humidity Level: 80%
  • UVB lighting: Highly Recommended
  • Average price range: $650 – $1,200
  • Conservation Status: Not listed
Emerald Tree Monitor (Varanus prasinus) at the bioparc fuengirola (1)
Varanus prasinus
  • The Green Tree monitor goes by Varanus prasinus in scientific name. It is also called the Emerald monitor. It belongs to the Varanidae Family and Varanus Genus.
  • You can find Green Tree monitors living on the islands of and adjacent to New Guinea. You can see them living together as a group. There’s always a dominant male among several females. Other males are juveniles.
  • Adults can grow up to 3 feet long, and the tail measures twice its body length. It’s one slender lizard to have for a pet. The colors range from dark jade to lime green.
  • You can observe black spots or patterns across the tail and body. Sometimes, the black markings may be V-shaped from its neck downwards.
  • The Green Tree monitor has long claws, and along with the tail, this pet reptile can grip, climb, and swing on tree branches with ease and agility.
  • Female tree monitors have been known to use termite mounds as nesting chambers. This is because the temperature conditions and humidity level create the ideal incubator.
  • Green tree monitors like to swim in ponds and streams. So, if you have one as a pet, they would love to have a shallow water bin on the ground.

Green Tree Monitor Care Sheet

Green Tree Monitor Habitat

Varanus prasinus (Green Tree Monitor)
Emerald Tree Monitor

In its native Habitat, Green tree monitors are at home among trees of the rainforests. These love climbing treetops and viIn its native Habitat, Green tree monitors are at home among trees of the rainforests. They love climbing treetops and vines. They also like to have plenty of places available to hide, things to play with, and areas to explore.


You can design and build a tall or vertical enclosure for your Green tree monitor. Remember to provide your pet reptile a large enough space to move and climb in. Twice its length is a good reference measurement.

You can use plastic, glass, or wood as materials. There should also be enough room to include lots of branches, reptile hides, and nesting boxes.


Reptile enclosures accumulate fecal matter, food particles, and other debris. That’s why you should schedule daily cleaning in addition to weekly sanitation and disinfecting of your Green tree monitor’s enclosure.

Scrub the walls and wash the water bowl daily. Use cleaning agents that are safe for your pet monitor lizard.


Choose a substrate that makes it easy for your pet Green tree monitor to dig and hide under. You can combine different types for variety. For options, you have moss, cypress, soil, and more.

Those that promote humidity are best to use. Buy misters for easy misting. Also, consider having leaf filters for a substrate. They help with moisture and allows your pet Green monitor to dig easily.

Temperature and Humidity

Green tree monitors naturally do best with a hot and humid climate. Maintain temperatures around 25-26 °C. Position a basking light on one side of the enclosure to provide your pet Green tree monitor a specific place where it can enjoy more heat.

Aim to keep night temperatures to no less than 21°C during nighttime. You may use a separate thermometer or built-in thermostat to help monitor and maintain proper temperatures.

Keep a bowl of fresh water to help with humidity. Misting your enclosure and the substrate also helps. You can check out automatic cage misters to make the task easier.


Provide a basking light for your pet Green tree monitor. You can place it along branches so it can enjoy the heat while perched on a branch. Consider UVB lights as these function like the sun’s rays that promote Vitamin D. 43°C is good enough for a basking light.

Remember to put a barrier or screen between the bulb and your Green tree monitor, or else your pet may become injured or suffer burns when it comes in contact with the bulb.


As we already mentioned, climbing branches, vines, and plants will put your pet Green tree monitor at ease in its new home. It is a natural climber. Buy sturdy branches since your pet reptile will surely spend a lot of time on them.

Plants provide cover and make your pet lizard feel more secure. Provide hide boxes as your Green tree monitor tends to hide away, especially at the start. A wide log is also a good accessory for your enclosure.

Green Tree Monitor Feeding

Green Tree Monitor perched on branch
Emerald Tree Monitor

Feeding your Green tree monitor is not difficult. It may not be able to feed on most standard prey, but you can give your pet large mice or rats.

For variety, you can alternate the Emerald tree monitor’s diet with mealworms, eggs, roachescrickets, small mice, and other large insects. A green tree monitor may find the hair of rodents hard to digest, so give yours some rat pinkies if they’re available.

Feeding can be regular. You can do it every other day. However, if you get a young one for a pet, expect rapid growth within three months of its life. It can reach a 400% weight rate in that amount of time, and the length can double.

They are mature by the second year, with the males growing faster in size than the females. Avoid accidental bites; buy tongs for safety. Consider dusting its food with Calcium.

Temperament and Handling

Defensive behavior is common not just among juveniles but even adults, especially when they newly arrive. Therefore, handle them less in the early stages to avoid bites and scratches.

In due time, they’ll get calmer around you and in their new surroundings. Increase handling time once you start earning your pet Green tree monitor’s trust.

They are not aggressive by nature but will still bite you if they feel threatened. Always use caution with a new and untrained pet.

Also, keep in mind that they are going to be much more active during the day. So, you can see them climbing, playing, and exploring their enclosure. As we have previously mentioned, they are arboreal, meaning they love to climb, so make sure there are plenty of climbing enhancements in their enclosure to keep them occupied and happy.


Emerald Tree Monitor
Green Tree Monitor

Care for your Green tree monitor properly, and it can be your companion for 15 years. Males and females reach reproductive sexual maturity by the age of 2, but males tend to grow faster than females and reach a larger size.

In the wild, Green tree monitors can live up to as long as 20 years. Larger monitors seem to live longer than the other smaller species.

Common Health Concerns (Issues/Solutions)

Dehydration is a common ailment, especially among wild-caught species. It is important to provide your pet Green Tree monitor fresh water daily.

Monitor its hydration upon arrival and make sure that it takes in enough water. Hydrate it, especially before each feeding. Death before hatching (even among fully-grown ones still inside the egg) is also common in a captive breeding environment.

Parasites are another health issue you will want to monitor and stay on top of. To do this, it is important to get fecal testing done regularly. It should be tested before you bring it home and then tested regularly after as well.

If you begin noticing that your pet is not eating well and seems sluggish or lethargic, or there is excess mucus, these could be signs of a respiratory infection. It is actually a common type of infection for the Green tree monitor, but it does require medical attention.

Pricing and Availability

Captive breeders offer Green tree monitors for sale at different prices. For example, you may find babies or adult Green tree monitor lizards on sale for $650 and up to $1,200.  Prices can be highly expensive because captive breeding rates are low, and most in captivity are wild-caught.


Indonesia has some conservation laws for Green tree monitors. Expect strict implementation, especially within protected reserves.

There seem to be no high risk or great threats since these reptiles are easy to adapt to any surroundings. The survival rate is good even in modified habitats as long as there are prey and trees within the environment.

With captive breeding in place, the rate of illegal pet trade is not significant. Although it does exist in some wild populations, the likelihood of a population decline is currently minimal.

Green Tree Monitor Overview Video


Do Green tree monitors make good pets?

Yes. Green tree monitors are highly intelligent and do make great pets. However, they aren’t a pet for everyone. Excessive handling should be avoided when you first get the pet to give the lizard time to get used to you as its new handler.

Remember, it takes time to train and tame your lizard, so if you lack the patience and time required to care for it, this is not the right pet for you. Also, these lizards require a fair amount of experience and commitment, so they will not be beginner-friendly pets.

How big does a green tree monitor get?

Most Green tree monitors will reach a length of about three feet, with their tails being twice as long as the length of their body. The females also tend to be slightly smaller than their male counterparts.

Are green tree monitors endangered?

The conservation status of the Green tree monitor is LC or least concern. The Green tree monitor, or Emerald tree monitor as it is also known as is currently protected under Indonesian law.

The species appears to be quite adaptable and has been found to survive in different modified habitats. There are currently no significant threats, and they are a well-managed species due to captive breeding programs.

Are tree monitors aggressive?

Some species are considered slower and more docile, while others have proven to be aggressive. However, the Green tree monitor is pretty shy and will not attack a human unless provoked or threatened.

If they are in defense mode, do not touch them, chase them, or corner them, as this can cause them to become increasingly agitated. Monitor lizards can secrete venom, but it is not at all fatal for humans. Your main concern after a bite would be a bacterial infection.

Final Words

The Green tree monitor lizard is truly an entertaining pet to keep. It is highly active and curious. It is sure to amuse and bond with its owner in due time.

Check with a local captive breeder for availability and any required permits in your state. Know the proper way to set up its enclosure and allow it to get used to its new home with the least possible stress.

To find a good pet Emerald monitor, check our guide for the best pet monitor lizards.

Earn its trust. Feed it right, and it will be your companion for a long time. Do you have any experience with this awesome creature? Share your insights in the comments below.

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