General Care Requirements

This guide focuses on the green iguana (Iguana iguana) and the rhinoceros iguana (Cyclura cornuta). Both require substantial accommodation, effective heating and UVB, and a carefully planned diet. Their habitat use differs, so their enclosures should not be identical. These recommendations should not automatically be applied to other iguanas, including spiny-tailed, desert or Fiji iguanas.

Natural Habitat

Green iguanas inhabit tropical environments in Central and South America. They spend considerable time in trees, often near water, using substantial branches for resting and basking. Captive housing should offer height, strong climbing structures and sheltered areas among foliage.

Rhinoceros iguanas originate from Hispaniola and nearby islands. Their habitats include rocky lowlands, scrub and seasonally dry forest. They use rock crevices, caves and burrows as retreats. Although predominantly ground-dwelling, they also climb and use elevated basking positions.

Housing

Plan the adult enclosure before acquiring a juvenile. Both species become powerful animals requiring purpose-built accommodation rather than a standard small terrarium.

• Green iguana: Approximately 300 × 150 × 180 cm is a published practical minimum recommendation for one adult, with larger housing preferable. Provide substantial elevated platforms and branches that support the entire animal.
• Rhinoceros iguana: Specialist zoo guidance gives approximately 180 × 180 × 180 cm as a baseline for one Cyclura, with additional space desirable. Prioritise usable floor area, digging opportunities, secure retreats and accessible basking platforms.

Dimensions are listed as length × width × height. These figures are husbandry recommendations rather than experimentally established welfare thresholds. Furnishings should leave enough room for the iguana to turn, walk and move between different environmental conditions.

Anchor heavy branches, platforms and rocks securely. Place heavy structures on a stable foundation so digging cannot undermine them. Provide sheltered resting places and visual barriers.

Individual housing is the safest starting arrangement for private keepers. Territorial behaviour, particularly during the breeding season, can result in serious injuries. Additional animals require separate accommodation to be available, even when introductions initially appear successful.

Temperature & Humidity

Green iguana: Provide daytime air temperatures across approximately 24–31°C, with a local basking surface around 50°C. A practical night-time target is approximately 23–25°C. Maintain daytime humidity around 60–80%, with natural increases at night.

Rhinoceros iguana: Provide warm daytime air around 29–32°C, cooler retreats around 25–28°C, and a basking surface approximately 40–50°C. Night-time temperatures around 22–25°C provide a useful reduction. Specialist rock iguana guidance describes humidity around 50–80%, with access to sheltered microhabitats.

Basking figures refer to surface temperatures, not the temperature of the entire enclosure or the animal’s body. Use an infrared thermometer for surfaces and digital probes for air temperatures.

The heated area should be broad enough to warm the body evenly. A small, intense hotspot can overheat one part of the animal while the remainder stays cool. Guard accessible heat sources, use suitable thermostatic control and ensure the iguana can retreat into shade.

Provide ventilation at all humidity levels. Green iguana housing should retain moisture without becoming stagnant, while rhinoceros iguanas should have dry exposed resting surfaces as well as access to more humid retreats. A seasonally dry natural habitat does not mean the animal should be kept dehydrated.

Lighting & UVB

Provide bright daytime lighting, effective UVB and a regular dark period at night. Approximately 12–13 hours of daytime lighting is a practical starting schedule, with seasonal adjustments where appropriate.

Arrange heat, visible light and UVB over the basking area, while providing shade and sheltered retreats. The animal should be able to change its exposure voluntarily.

For green iguanas, approximately UVI 3–4 at the animal’s back in the basking position is a practical published target. Rhinoceros iguanas are classified as more exposed baskers in the UV-Tool and require a species-appropriate lighting design rather than automatically copying the green iguana setup.

Use a UV Index meter to check the installed system where possible. Lamp strength, reflector, distance and mesh affect exposure. Ordinary glass between the lamp and animal blocks useful UVB. Dietary vitamin D3 should not be treated as a straightforward replacement for appropriate lighting.

Feeding

Green iguanas require a plant-based diet. Offer a varied mixture of leafy greens and suitable browse, supplemented with vegetables and edible flowers. Useful ingredients include dandelion leaves, endive, escarole, collard greens, squash and pesticide-free hibiscus flowers.

Make leafy foods the foundation rather than feeding mainly fruit or watery lettuce. Fruit should remain a small addition. Do not provide insects, meat, eggs, or dog and cat food as routine green iguana foods.

Rhinoceros iguanas also require a predominantly plant-based diet, including leafy browse, greens, vegetables and flowers. Some managed zoo diets include small amounts of animal matter, but this does not justify a meat-rich diet or copying the feeding routine of an insect-eating lizard.

Feed growing animals daily. Adults can generally receive appropriately portioned meals daily, with quantity and frequency adjusted to body condition and activity. Remove spoiled food and avoid continually increasing portions simply because an iguana readily accepts more.

Provide an appropriate calcium and vitamin programme for the actual diet and UVB provision. Follow the selected supplement’s directions and avoid stacking several products containing vitamin D3 or vitamin A.

Water & Reproductive Care

Fresh drinking water should always be available in a stable, accessible container. Green iguanas can be offered a larger container for bathing, provided that entering and leaving it is easy. Clean bathing water promptly when soiled.

Misting and moisture-retaining furnishings can help maintain suitable humidity, but they do not replace drinking water.

Females can develop eggs without having mated. Provide a suitable, accessible nesting area with enough digging depth and space for the female to excavate a nest. Persistent straining, repeated unsuccessful nesting attempts or weakness requires prompt veterinary assessment.

Lifespan

Green iguanas commonly have reported captive lifespans of approximately 15–20 years, with some living longer.

Rhinoceros iguanas can live for several decades. A documented captive individual exceeded 40 years; this is a longevity record, not an average lifespan. Plan for a long-term commitment rather than assuming that care will only be needed for a few years.

Common Health Challenges

• Metabolic bone disease: Inadequate calcium balance or vitamin D3 provision can impair skeletal health. Weakness, swollen limbs or jaw changes require veterinary assessment.
• Obesity: Excessive feeding and insufficient activity can cause unhealthy weight gain. Monitor body condition rather than feeding solely according to appetite.
• Kidney disease and gout: These can have several causes, including chronic dehydration and inappropriate nutrition. Prevention involves suitable hydration and diet rather than relying on one supplement.
• Thermal injury: Unguarded heaters, hot surfaces and concentrated basking hotspots can cause burns.
• Reproductive disorders: Egg retention and other reproductive problems can occur in females, including those kept without a male.
• Bladder stones: Urinary stones can interfere with normal elimination and may require veterinary treatment.
• Parasites: Persistent weight loss, abnormal droppings or poor condition can warrant faecal testing and further investigation.
• Traumatic injuries: Territorial encounters, insecure furnishings and unsuitable restraints can cause wounds or fractures. Never lift or restrain an iguana by its tail.