🦎 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.

1. 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

  • 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

2. 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

  • 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

3. Humidity & Water

Humidity

  • High 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

4. Diet

Emerald Tree Monitors are 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

5. Behavior & Handling

Temperament

  • Intelligent, active, and alert

  • Arboreal and fast; juveniles can be defensive

  • Adults may tolerate careful handling with experience

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

6. 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

Vet Care

  • Consult a reptile veterinarian for serious symptoms

  • Routine check-ups recommended, especially for arboreal monitors

🦎 Final Notes

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 fascinating, long-term companions.