Green iguana
Iguana iguana
Photo: Iguana in the Maracaibo wild · Wilfredor · CC BY-SA 3.0 · Changes and credits
These guides provide general husbandry information and do not replace veterinary assessment. If your animal shows symptoms or its condition worsens, contact a veterinarian experienced with exotic animals.
- Warm zone
- Basking surface: 50 °C
- Cool zone
- Cool air: 24–31 °C
These notices cover the cited provisions, not every possible national or local rule. Check additional requirements with the competent authority.
Description
Iguana iguana is a large arboreal lizard from tropical America. It has a long tail, dorsal crest and broad dewlap also used in visual communication. Colour changes with age and origin and is not always green. It is diurnal, mainly herbivorous and able to swim and dive to escape predators.
Behaviour
Response to contact varies: observe the individual’s stress signals.
Housing together
Keep one adult per enclosure for routine maintenance. Do not add a second male or treat a male-female pair as permanent non-breeding housing: pursuit, biting and monopolised basking access require separation. Breeding encounters take place under observation with a second enclosure ready.
Enclosure and climate
Provide a tall structure with sturdy platforms and retreats. Maintain a measured thermal gradient and prevent contact with lamps and heaters. Test the enclosure before arrival, using air probes and measuring surfaces separately.
Night: 23–28 °C.
Making height usable
Secure horizontal, sloping and vertical branches to the structure, using diameters that offer grip and supports suitable for adult weight. Connect them from the exposed lighting branch to the cool area, distributing supports across levels. Place hide entrances beside branches; add foliage along routes without blocking dishes, doors or vents.
Testing and access
Connect specified heat sources to compatible thermostats and guard against contact. Secure probes according to device instructions; measure air at resting sites and heated surfaces separately with independent instruments. In housing with water, also check water temperature and quality: one zone’s thermostat does not control the others.
With the complete enclosure running, record day and night readings and compare them with the sheet. Test doors, cable openings and cleaning access, keeping vents clear. Change one variable at a time and recheck after each adjustment.
Lighting and UVB
Ferguson zone not assigned with sufficient precision to this taxon.
At the exposed position aim for approximately UVI 3–4, measured at the back or head. The animal must choose its exposure and reach UVI 0 retreats. This local target differs from the Ferguson ecological band and should not be maintained everywhere throughout the day.
UVB is essential in indoor housing. Outdoors, direct sunlight can provide it if shade is always accessible. Select the lamp to achieve the appropriate UVI at the positions the animal uses.
UVA is recommended as part of daytime lighting, including when UVB has not been shown to be indispensable. Check the UVB source’s spectrum, as it may already emit UVA: a second lamp is not automatically necessary.
Linear UVB tube with reflector. Indicative UVB percentage stated on the lamp: 5–7%; final selection depends on UVI achieved at the actual distance.
For maintenance, a cycle of approximately 12 hours of light and 12 hours of darkness can serve as an initial reference. Use a timer to switch lights off at night, and keep retreats available so the animal can withdraw from light during the day. Adapt day length to species and origin, following the specific guidance for seasonal care and breeding.
Light in the animal’s daily life
Verify a broad patch for the adult, including back and crest height. Measuring only the platform centre does not establish adequate coverage for a large animal.
An example layout in the enclosure
To make the layout concrete, take housing measuring 300 × 150 × 180 cm, using the first dimensional configuration in the sheet. This is a mounting example: retain the conditions and any alternatives attached to the stated minimum.
In a wooden enclosure with internal lighting, imagine the tube 175 cm above the floor and the back or head at 135 cm. The geometric distance is therefore 40 cm. The branch or platform lies below animal height, according to body size. Place lighting over one side, with a route to fully screened retreats.
In a glass enclosure with a mesh roof, retain the same animal height and imagine the tube 5 cm above the mesh: distance becomes 50 cm. Mesh attenuates UV variably; ordinary glass roofs block UVB. Increasing the percentage alone is insufficient: measure beneath the mesh and adjust height, output or layout as needed.
These distances describe the example, not a safe clearance for every lamp. Select the source and adjust mounting until approximately UVI 3–4 is measured at animal height in the exposed position. Also respect the minimum clearance specified for the model used. Recheck with furnishings, guards and mesh installed, including the highest reachable points and animal growth.
Choosing and checking lighting
First define the patch that should illuminate the whole body and the route to a screened retreat. For a broad patch, select a linear tube with reflector; consider a compact only if its useful patch covers the body and leaves an accessible gradient. Check model, output, reflector and mounting distance, then compare measured UVI with the species target. Label UVB percentage alone cannot determine distance and intensity.
The decisive check uses a UVI metre facing the source at animal height. Check the centre and edges of the exposed patch, the highest supports and retreats, which must allow withdrawal from UV. Repeat after moving equipment, changing lamps and plant growth. Without a metre, use the manufacturer’s instructions and measurements for the exact configuration, including safety clearances.
When UVB or UVA are absent
If the UVB source fails, restore the installation and recheck the exposed area. Oral D3 may be considered as temporary support but is not a complete or universally safe replacement. Consider calcium, D3, diet and animal condition together: avoid improvised extra doses.
UVA contributes to environmental perception and behaviour and cannot be replaced by vitamins or calcium. A reptile UVB source normally also emits UVA: check its declared spectrum. If the existing lighting lacks it, complete the installation with a suitable source; an ordinary white LED does not guarantee UVA and a UVA-only lamp does not provide UVB.
Humidity and ventilation
Mist leaves and branches, leaving reachable droplets for drinking; allow surfaces to dry between water inputs. Measure beside perches outside the spray and keep vents behind foliage clear.
Feeding
Iguana iguana is herbivorous. Rotate fibre-rich leaves and identified plants; do not add insects or meat for rapid growth.
Recommended foods
The tiers describe dietary use: rotate foods within each tier rather than treating them as an absolute nutritional score.
| Food | Dietary role | Benefits and limits | Preparation |
|---|---|---|---|
| Chicory, endive, dandelion and other edible leaves | Main choices | Supply fibre and varied minerals with lower energy density than fruit and seeds. Rotate plant species: no single leaf balances the whole diet. | Identify plants, wash and cut into manageable pieces. Avoid treated plants, unidentified ornamentals and iceberg lettuce as the only green. |
| Squash, courgette, edible flowers and varied vegetables | For rotation | Add variety, but soft vegetables should not replace all fibrous leaves. | Wash, remove hard seeds and chop; mix with leaves to discourage selective feeding. |
| Fibre-rich complete herbivorous reptile food | For rotation | Can supplement plant availability, but must suit the species rather than being a mixture of cereals or dried fruit. | Follow the dose and any soaking instructions; replace part of the meal. Do not automatically add supplements already present. |
| Ripe fruit | Occasional | Rich in water and sugar and not a complete food; offer a small taste replacing part of the meal. | Wash and remove stones and large seeds; no syrup-preserved fruit, honey or added sugar. |
| Meat, insects, dog or cat food | Avoid / not a staple | Unsuitable as a diet for these herbivores: they displace fibre and increase protein and energy without matching the species’ digestion. | Do not use them to accelerate growth or “strengthen” a debilitated animal. |
Meals by age and size
| Stage and size | Frequency | Amount per meal |
|---|---|---|
| Young and growing juveniles | Daily, plants cut to mouth size | Cover the dish with a loose layer of leaves; photograph or weigh the portion and leftovers. Increase if finished and growth stays steady; reduce energy-dense foods if fat increases. Do not compress a large mound into a small dish. |
| Subadults and adults | Daily, after morning warming | Cover the dish with a loose layer of leaves; photograph or weigh the portion and leftovers. Increase if finished and growth stays steady; reduce energy-dense foods if fat increases. Do not compress a large mound into a small dish. |
Adjusting portions
Compare the amount of plants offered and the leftovers with observed growth. Weekly weighing of juveniles and monthly weighing of adults helps follow the trend. Increase portions gradually if growth remains steady without fat accumulation; reduce them if body condition indicates excess weight or leftovers remain. Assess the cause of weight loss before increasing meals.
Preparing and offering meals
Wash leaves, identify all collected plants and discard treated, mouldy or unknown plants. Offer on a clean dish or safe grazing area; remove spoiled produce and keep fresh water available.
Calcium and vitamins
Apply a thin even coating of phosphorus-free calcium to a fresh plant meal. Use a herbivore multivitamin at the interval specified for its formulation, accounting for any complete diet: do not add the same dose to already fortified pellets.
Oral D3, UVB exposure and fat-soluble vitamins must form one programme. Cuttlebone can remain available for tortoises, but does not guarantee that each animal consumes enough calcium.
Daily care
First days
Record identity and origin and prepare separate housing. Before arrival, check closures, water and retreats. Offer the foods in the sheet and record intake, leftovers and weight. Follow a quiet maintenance routine and keep hides available, avoiding capture just to observe the animal.
Cleaning
Keep animals and equipment away from kitchens and food areas, use tools dedicated to each enclosure and wash your hands with soap and running water after handling animals, food, tank water or furnishings. Quarantine new arrivals separately and agree the duration and checks with a veterinarian before introducing them to established animals.
Handling
Prepare the transfer container near the animal with a reachable entrance. Where possible, guide it into the container without chasing it around the enclosure. Close the container before moving it and check that it is secure; do not grip the tail or limbs and limit contact to necessary transfers.
Checks
Weight loss, weakness, injuries or abnormal breathing warrant veterinary assessment.
Record appetite, droppings and environmental changes; a check is not an automatic treatment.
Breeding
Sex, maturity and readiness
Femoral pores and tail characteristics help identify adult males; maturity can precede adequate body reserves. Prepare very large enclosures and a complete herbivorous feeding plan without increasing animal protein to “condition” females.
Start a record for each breeding animal with identity, origin, documented age and previous weights. Compare the weight trend with growth and body condition; delay introductions for animals still growing rapidly, losing weight or recently acquired. Use stated ages as guidance alongside these checks. If sex cannot be identified reliably, obtain assessment by qualified personnel before pairing.
Preparation and seasonal cycle
Season may strongly change appetite and territoriality. Introduce a pair only with secure dividers and monitor male biting; promptly separate when females cannot retreat. Even isolated females may develop eggs.
Before encounters, prepare and test offspring enclosures and have first foods available. Check records for regular adult feeding and good body condition, then verify access from exposed areas to retreats. If the species protocol includes seasonal changes, adjust settings gradually and record the response. Record night-time air, surface and egg temperatures separately, noting where each is measured. Keep water available throughout preparation.
Courtship and mating
Introduce only identified, compatible adults, with another enclosure ready. Observe from a distance and end the encounter if you observe persistent pursuit, injuries or an animal unable to move away from its partner; do not forcibly separate animals during copulation. Record the date, both identities and what you actually saw: courtship, contact or mating alone does not prove fertilisation.
Before laying and the nest
Prepare a large opaque accessible box beforehand, with moist soil and sand deep enough for digging. Females may reduce food intake as the abdomen enlarges; retain water, selectable warmth and privacy. Do not palpate or squeeze the abdomen to count eggs.
Maintain a suitable laying site even without a male: females can produce unfertilised eggs. Persistent straining without laying, weakness or tissue protruding from the vent require prompt veterinary assessment. Do not wait for a predicted laying date if these signs appear. Do not squeeze the abdomen, pull eggs or give drugs to induce laying without veterinary direction.
Egg incubation
Retain orientation and joined eggs. Hatching at 73 days at 30 °C is reported in one covered system, while other conditions take 90–120 days: do not conflate these intervals. Use moist substrate, controlled air exchange and no domestic antifungal treatments on shells.
Test the system before laying with an independent probe at egg height. Use clean, labelled containers, closed but allowing air exchange, with room for eggs and hatchlings. Keep eggs in their original orientation and do not detach eggs glued to their support. The substrate should retain moisture without free water on the shell; check condensation and water loss, adding water at the edge of the substrate rather than onto eggs. Record temperature and events daily without needless opening. The stated times are approximate: do not increase heat to meet a date.
First meals and juvenile care
Offer finely chopped calcium-rich plant food and shallow water after yolk absorption. Hatchlings are herbivorous like adults: do not use insect or meat diets. Prepare branches, UVB and shelter and ensure smaller animals are not excluded from food.
During the first weeks, monitor each youngster: a feeding group does not guarantee that every individual eats. Record intake, droppings and weight at regular intervals to follow growth and adapt housing and food size. Provide separate accommodation if competition prevents an individual from feeding or size differences become marked. Document repeated independent meals before transfer to another keeper.
Female recovery
After reproduction provide water and the usual balanced diet, initially in manageable portions; monitor weight, activity and return of appetite. Keep supplements and lighting consistent with the feeding guide. Avoid further introductions until the previous condition has recovered; later clutches may occur without another mating. Persistent straining, weakness or protruding tissue require veterinary attention, without squeezing the abdomen.
Equipment and example diary
Place the nest where it can be checked without dismantling the enclosure. Label containers with female identity and laying date and prepare the specified medium; for attached eggs, instead provide guards in place without detaching them. If using an incubator, install a thermostat and independent probe and test it before laying. Run offspring enclosures too and prepare scales and first food, reserving capacity for later clutches.
A consistent diary using actual dates helps follow reproduction in Iguana iguana. Start with adult identity, weight and condition, then record observed encounters, laying or birth and development conditions. After emergence record the first meal actually accepted and each youngster’s growth while continuing to follow female recovery. Over time these records help identify your lineage’s pattern without turning approximate durations into deadlines.