🦎 General Info

Crocodile Monitors (Varanus salvadorii) are among the largest and most powerful lizards in the world, native to the forests and wetlands of New Guinea. They are named for their long, crocodile-like tail and body, and can reach 8–10+ feet in total length, with males generally larger than females.

Crocodile Monitors are intelligent, strong, and highly active, capable of recognizing experienced keepers. They are semi-arboreal and semi-aquatic, requiring extremely spacious enclosures, climbing opportunities, swimming areas, and a varied diet. These lizards are not suitable for beginners due to their size, strength, and high activity level. With proper care, they can live 20+ years in captivity.

1. Enclosure

Size

Crocodile Monitors require extremely large and secure enclosures:

  • Juveniles: Minimum 8 ft x 4 ft x 4 ft

  • Subadults: Minimum 12 ft x 6 ft x 6 ft

  • Adults: Minimum 20 ft x 10 ft x 10 ft (larger is ideal)

Provide climbing structures, water for swimming, and large open spaces for roaming.

Material

  • Strong PVC, custom wooden builds, or reinforced glass/mesh vivariums

  • Must be extremely secure, as Crocodile Monitors are fast, strong, and excellent climbers and diggers

  • Adequate ventilation is essential

Substrate

  • Moisture-retentive substrates suitable for digging:

    • Cypress mulch

    • Coconut husk

    • Organic topsoil/sand mix

  • Depth: 8–12 inches for natural digging

Décor

  • Large, sturdy branches, logs, and rocks for climbing

  • Hides on both warm and cool sides

  • Large water area for swimming and soaking

  • Live or artificial plants for cover

  • Plenty of open floor space for roaming and hunting enrichment

2. Temperature & Lighting

Basking Spot

  • 115–125°F for proper digestion and metabolism

Ambient Temperature

  • 80–90°F during the day

  • Cool side: 75–80°F

  • Night Temperature: 70–75°F (do not let temps drop below 70°F)

UVB Lighting

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

  • Replace bulbs every 6–12 months

  • Crocodile 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

  • Moderate to high humidity: 70–80%

  • Supports skin health, shedding, and hydration

  • Provide misting or a humidifier as needed

Water

  • Provide a very large water feature for swimming and soaking

  • Change water daily or when dirty

  • Juveniles may benefit from more frequent soaking

4. Diet

Crocodile Monitors are carnivorous, requiring a varied protein-rich diet.

Staple Foods

  • Rodents: mice, rats, chicks

  • Fish and crustaceans

  • Insects: crickets, roaches, earthworms

Occasional Treats

  • Eggs

  • Lean meats (chicken, turkey, fish)

  • Small amphibians occasionally

Supplements

  • Calcium powder: 3–4× per week

  • Reptile multivitamin: 1–2× per week

  • Avoid overfeeding fatty foods

5. Behavior & Handling

Temperament

  • Highly intelligent, strong, and active

  • Juveniles can be defensive; adults may tolerate careful handling with experience

  • Extremely fast and powerful; not suitable for beginners

Handling

  • Support the entire body; never lift by tail or limbs

  • Use protective gloves or tools for safe interaction

  • Short, careful sessions are recommended

Enrichment

  • Large water area for swimming

  • Climbing branches and sturdy logs

  • Deep substrate for digging and exploring

  • Scent trails or live prey for mental stimulation

6. Health & Lifespan

Lifespan

  • 20+ years with proper care

Common Health Issues

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

  • Obesity: overfeeding or low activity can lead to weight problems

  • Respiratory infections: from low temperatures or improper humidity

  • Parasites: monitor feces regularly

Signs of Illness

  • Lethargy or refusal to eat

  • Swollen limbs or joints

  • Respiratory wheezing or discharge

  • Poor shedding or retained skin

  • Sudden weight loss or bloating

Vet Care

  • Consult a reptile veterinarian for serious symptoms

  • Routine check-ups are recommended, especially due to their size and strength

🦎 Final Notes

Crocodile Monitors are extremely large, intelligent, and active reptiles suitable only for highly experienced keepers. They require massive, secure enclosures, climbing opportunities, swimming areas, proper heat and UVB, a protein-rich diet, and enrichment. With correct care, they thrive, display natural behaviors, and can become fascinating, long-term companions.