🦎 General Info

Emerald Tree Monitors (Varanus prasinus) are small-to-medium, highly arboreal lizards native to New Guinea and surrounding islands. They are renowned for their vibrant emerald green coloration, long prehensile tails, and slender bodies. Adults typically reach 2–3 feet in total length, with males slightly larger than females.

Emerald Tree Monitors are intelligent, active, and arboreal, thriving in vertical enclosures with climbing opportunities. They are fast, agile, and require experienced keepers familiar with handling and proper care. With optimal care, Emerald Tree Monitors can live 12–15+ years in captivity.

Enclosure

  • Size: Emerald Tree Monitors are highly arboreal and require tall, spacious enclosures:

    • Juveniles: Minimum 3 ft x 2 ft x 4 ft (L x W x H)

    • Subadults: Minimum 4 ft x 3 ft x 6 ft

    • Adults: Minimum 6 ft x 4 ft x 8 ft (larger is ideal)

    • Vertical space is critical for climbing and exercise.

  • Material

    • PVC or mesh enclosures, custom wooden vivariums, or large glass terrariums with secure mesh tops

    • Must be extremely secure, as Emerald Tree Monitors are fast and excellent climbers making them great escape artists

    • Adequate ventilation is essential

  • Substrate

    • Moisture-retentive substrates suitable for burrowing at the base:

    • Cypress mulch

    • Coconut husk

    • Organic topsoil/sand mix

    • Depth: 2–4 inches is sufficient for arboreal species

  • Décor

    • Branches, vines, and climbing structures

    • Vertical hides and elevated basking areas

    • Shallow water dish for drinking and soaking

    • Live or artificial plants for cover

    • Plenty of vertical and horizontal climbing space

Temperature & Lighting

  • Basking Spot: 95–105°F for proper digestion and metabolism

  • Ambient Temperature: 80–88°F during the day

  • Cool side: 75–80°F

  • Night Temperature: 70–75°F

  • UVB Lighting

    • Some keepers have had success with NOT using UVB with proper diet, however UVB can be very beneficial for your monitor

    • High-quality T5 HO 10–12% UVB is essential for bone health

    • Replace bulbs every 6–12 months

    • Emerald Tree Monitors are diurnal and require full-spectrum lighting

    • Day/Night Cycle 12–14 hours of light daily

    • Mimics natural diurnal activity patterns

Humidity & Water

  • Humidity: 70–80%

    • Supports skin health, shedding, and hydration

    • Misting or automated humidifiers recommended

  • Water

    • Provide a shallow water dish for drinking and occasional soaking

    • Change water daily or when dirty

    • Juveniles benefit from additional misting to maintain hydration

Diet

  • Type: Primarily insectivorous, requiring a high-protein diet with occasional supplementation.

  • Staple Foods

    • Insects: crickets, roaches, mealworms, superworms, waxworms

    • Occasional small fish or pinky mice (sparingly for adults)

  • Occasional Treats

    • Egg (hard-boiled or cooked)

    • Small portions of lean meat (sparingly)

  • Supplements

    • Calcium powder: 3–4× per week

    • Reptile multivitamin: 1–2× per week

    • Avoid overfeeding fatty foods

Behavior & Handling

  • Temperament: Emerald Tree Monitors are highly intelligent like other monitor species. They are active and alert of their surroundings as they climb around in their enclosure. Juveniles are usually pretty defensive but with work in patients with handling they do tend to tame down.

  • Handling

    • Support the full body; avoid sudden movements

    • Use gloves or handling tools if necessary

    • Handle in short sessions to reduce stress

  • Enrichment

    • Vertical climbing branches, vines, and perches

    • Live or artificial plants for cover

    • Scent trails or insects for hunting stimulation

    • Rearrange décor periodically to encourage exploration

Health & Lifespan

  • Lifespan: 12–15+ years with proper care

  • Common Health Issues

    • Metabolic Bone Disease (MBD): from poor UVB or calcium deficiency

    • Obesity: less common, but overfeeding fatty foods should be avoided

    • Respiratory infections: from low temps or excessive humidity without ventilation

    • Parasites: monitor feces regularly

  • Signs of Illness

    • Lethargy or refusal to eat

    • Poor shedding or retained skin

    • Respiratory wheezing or discharge

    • Sudden weight loss or bloating

  • Veterinary Care: Professional veterinary care should always be consulted when you think your pet may have an issue. Watch for signs of illness, catching an issue early on goes a long way.

🦎 Final Thoughts

Emerald Tree Monitors are intelligent, fast, and highly arboreal reptiles best suited for experienced keepers. They require tall, spacious enclosures, high humidity, proper heat and UVB, a protein-rich diet, and climbing enrichment. With correct care, they thrive, display natural behaviors, and can become