Rhino iguanas (Cyclura cornuta) are 4.5’ long, diurnal, terrestrial reptiles native to the island of Hispaniola in the Caribbean. They prefer rocky, fairly dry environments such as tropical dry forest, lowland scrub, and coastal forest.

Rhino iguanas are generally dull gray to beige in color, True to their common name, they have a noteworthy horn-like projection on their snout, although they also have a large protuberance on top of their head, behind the eyes, and a series of crests along the spine. Males are typically larger than females, with more developed crests and “horns.”

Due to their size and housing requirements, rhino iguanas are an advanced-level pet reptile. With good care, they can live well over 20 years.

How much space do rhino iguanas need?

Because of their large size, a single rhino iguana should be housed in no smaller than a 8’L x 4’W x 4’H enclosure. If at all possible, larger is strongly recommended, in addition to regular opportunities to free-roam (supervised) for exercise. This size of enclosure is not typically available for purchase, so you will likely need to order one custom-made or build your own.

Cohabitation (keeping multiple iguanas in the same enclosure) is not recommended.

Do rhino iguanas need UVB?

Yes, rhino iguanas require UVB lighting as part of their captive setup. Aside from helping provide a day/night cycle and providing an infinite supply of vitamin D, UVB is also good for the lizard’s overall health. 

Here are the best UVB bulbs for rhino iguanas housed in an indoor 8’L x 4’W x 4’H enclosure:

• Arcadia Desert 12%, 46”
• Zoo Med Reptisun T5 HO 10.0, 46”

If your rhino iguana is housed outdoors in an appropriate climate, supplementary UVB is not likely to be necessary.

Your UVB lamp should be mounted inside the enclosure and positioned on the warm side of the setup. Place the basking platform so your rhino iguana’s back will be 17-18” below the lamp. The UVB bulb should be housed in a reflective fixture like the Arcadia ProT5 or Vivarium Electronics. Make sure that the fixture your UVB bulb is housed in does not have a clear plastic bulb cover.

Rhino iguanas are diurnal, which means that they are most active during the day. It’s best to provide 13 hours of light during summer and 11 hours during winter. This simulates natural seasonal changes in day length and encourages healthier hormonal rhythms.

Since rhino iguanas are active during the day, it’s also beneficial to provide an additional daylight-spectrum lamp to make sure the enclosure is brightly illuminated. This is extra important since you will be using such a large enclosure. Use 6’ of strong 6500K LED or T5 HO fluorescent plant grow lights for best results.

What basking temperatures do rhino iguanas need?

Rhino iguanas need a basking air temperature around 106°F, although surface temperatures may be higher. Air temperature throughout the rest of the enclosure can vary between 75-88°F, and nighttime temps can drop down to 70°F. Temperatures should never go below 62°F for any length of time!

To make sure your rhino iguana has access to the temperatures it needs, you will need a wall-mounted digital thermometer next to the basking platform to measure basking air temperature. Temperatures elsewhere in the enclosure can be measured with an infrared thermometer (“temp gun”).

Provide heat for your iguana by imitating the sun with a cluster of halogen heat lamps placed on one side of the enclosure. You will need enough lamps to evenly heat an area at least the size of the lizard’s body. Do not use ceramic heat emitters (CHEs), heat mats, red bulbs, or blue bulbs, as these are not as effective. Heating should be turned off at night.

If your rhino iguana is housed outdoors in a suitable climate, then supplementary heating is unlikely to be necessary.

What humidity levels do rhino iguanas need?

Rhino iguanas are associated with habitats that receive low amounts of precipitation, but due to their coastal nature, they still need a fair amount of ambient humidity. Target air humidity levels around 60%, measured with a wall-mounted digital hygrometer.

To increase ambient humidity, use a pressure sprayer or automatic misting system 1-2x/day..

What substrate is good for rhino iguanas?

Using substrate in your rhino iguana’s enclosure is important because of their terrestrial nature. Substrate covers the floor, cushions your pet’s body, helps maintain humidity, and gives the lizard something to dig around in. We recommend the following substrates for rhino iguanas:

• Zoo Med ReptiSand
• Exo Terra Desert Sand
• Play sand

Layering clean, chemical-free leaf litter on top of the substrate can help with humidity as well as add enrichment value.

Rhino iguanas are not particularly enthusiastic about burrowing, so substrate can be at least 4” deep. This should be completely replaced every 3-4 months. Remove poop and urates daily, along with any contaminated substrate.

What décor can you use in a rhino iguana enclosure?

Rhino iguanas are highly intelligent and curious animals, so it’s terribly boring for them to be stuck in an enclosure with nothing in it except a water bowl, basking platform, and somewhere to hide. It doesn’t matter how big the enclosure is if you don’t put things in it for your pet to use and interact with. 

Here are some ideas:

• sturdy climbing branches
• ledges/platforms
• hollow logs
• tree stumps
• additional hiding places (dog/cat kennels work well)
• live or artificial grasses

Climbing branches should be well anchored to the walls and/or floor of the enclosure to prevent collapse.

What do rhino iguanas eat?

Rhino iguanas are herbivorous, which means that they eat plants to get the nutrition that they need. Iguanas should be allowed to eat their fill every day on this schedule:

• Leafy greens daily
• Vegetables every other day
• Fruit 3x/week
• Commercial diet 3x/week

For a healthy, happy rhino iguana, offer as much dietary variety as you can! 

Leafy greens for iguanas: dandelion greens, collard greens, mustard greens, turnip greens, escarole, watercress, endive, chicory, chard, kale, spinach, bok choy, cilantro, parsley

Other vegetables for iguanas: green beans, snap peas, okra, parsnip, yucca root, bell peppers, carrots, beets, sweet potatoes, squash

Fruits for iguanas: figs, dates, papaya, mango, cactus fruit, berries, kiwi, apples, bananas, grapes, nectarines, pears, melon

Commercial diets for iguanas (moisten before feeding): Zoo Med Natural Iguana Food, Mazuri Small Tortoise Diet LS

Supplements

You will also need calcium and vitamin supplements to prevent your lizard from developing a deficiency. Use Repashy Supercal LoD 2-3x/week for juveniles and 1-2x/week for adults for calcium. Use Rep-Cal Herptivite weekly for juveniles and every other week for adults. These supplements should be lightly dusted over salads and mixed in before feeding.

Water

You will also need a large water bowl to help keep your rhino iguana hydrated. Keep the water clean and fresh at all times, and scrub the bowl with a reptile-safe disinfectant weekly, or whenever it becomes soiled with feces.

Do rhino iguanas like to be handled?

As adults, rhino iguanas are too large to be held, and as juveniles, they may be too skittish for handling. The key, instead, is to build a trusting relationship with your iguana so it will let you pet it and pick it up when needed. Offering food from feeding tweezers works well as an initial bribe, and it’s good to let the lizard get familiar with your presence by letting it see and hear you as often as possible. It’s best to get the lizard to come to you rather than simply grabbing it — a bite from a startled or defensive adult rhino iguana is no small thing! With patience, over time you can develop the relationship to the point where your rhino iguana will come running up to you when you come near.

If you need to pick up your rhino iguana, be gentle. Don’t grab the lizard from above — instead, approach from the side and scoop from below. Support as much of its body as possible, especially its feet, and hold it close to your body to help it feel secure during carrying.