Rhinoceros Iguana Care Sheet

Rhinoceros Iguana

Scientific Name

Common NameRhinoceros Iguana
Scientific NameCyclura cornuta
Life Span16.7 years or more; may have higher chances of living a longer life in captivity
Size60 to 136 centimeters (24 to 54 inches)
HabitatDry forest, scrub, desert
Country of OriginThe Hispaniola (currently the Dominican Republic and Haiti)
Conservation StatusEndangered

Physical Description

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Considered as one of the most unique Iguana species of the world, Rhinoceros Iguana is one of the precious biological features of the Caribbean, specifically in the island where they are endemic. These iguanas have evolved for thousands of years, to achieve their perfect adaptation against the extreme weather conditions of Haiti and the Dominican Republic that are only grounded with two seasons- the dry and wet.

Their name originated with their bony-plated horn-like organ which grows on their snout. Like the other lizards roaming in the wild, these iguanas have heavy heads, big dewlaps, massive legs, and powerful tails capable of whipping their intruders when they are threatened. They are also characterized by a crest of horned scales from the nape of their neck and extends to the tip of its tail.

They usually have a single color of either gray or brown. It is believed that their spines, horns, and other hard parts on their skin serve as their protective cover against various rocks and a form of escape from the grip of another iguana.

They are sexually dimorphic with males growing larger than the females, exhibit larger dorsal crests, and larger femoral pores, used for their communication with another iguana, especially during the mating season.


Two subspecies are falling under the Rhinoceros Iguanas. Both are known to live in Hispaniola and its nearby islands.

Navassa Island Iguana

Scientifically known as Cyclura cornuta onchiopsis, this subspecies living in the Island of Navassa is doubted to have already extinct due to human development in the said island. This iguana grows from 60 to 136 centimeters in length with a single-colored skin ranging from steel gray, dark green to brown.

It was first studied in the year 1885 and has gone extinct in the ‘60s during the military occupation in the said island. It is believed that mining activities and the military occupation itself, as well as the hunting activities, have made the population of the iguana in Navassa Island go dramatically decreased until it gone wiped out, as the 1999 studies carried out by the United States’ Avila College suggest.

Mona Ground Iguana

Another subspecies of the Rhinoceros Iguana, the Mona Ground Iguana is endemic to Mona Island and the largest terrestrial lizard to live in Puerto Rico up to the present times. They are known to grow up to 1.22 meters and are characterized by massive body growth and development, comparable to a monitor lizard.

Due to various factors, the Mona Ground Iguanas face the serious threat of extinction, classifying them as Endangered Species of IUCN. Their rapid decline of population is attributed to the feral pigs and over browsing goats on the island constantly looking for food, damaging the iguanas’ nest and killing its eggs during the breeding season.

Life Span

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Like the other reptiles of the world, a powerful Rhinoceros Iguana starts from its humble beginnings as a hatchling coming from its egg. As time passes by, their independence from their parents will give them the strength and prowess to master the art of survival under the scorching heat of the Caribbean Sun and to face natural challenges such as powerful earthquakes, typhoons, and volcanic eruptions.

The Hatchlings

As the breeding season ends, a mother iguana will lay her egg after a month or 40 days. The nests which are made by the females have their depths of about a meter and a half from the surface, offering the eggs the perfect incubation for their embryotic growth and actual hatch. The mother iguanas will soon abandon these eggs and start to live their lives alone, making it the most vulnerable moment of their lives since they came out from their mother’s womb.

Young Iguanas

Often characterized as quick and active, these iguanas are yet developing their senses and their bodies to get prepared for certain natural and animal-made conditions, especially with predation and calamities. At this moment of their lives, they develop their discipline in eating plants and wild fruits that can be seen in the forests of Hispaniola. However, the competition in food starts to increase as the scarcity with their sources becomes more usual as they grow bigger and demand more of something to be eaten. In some cases, if the vegetation is at its lowest, they tend to eat smaller animals such as crabs and carcasses of fishes or birds, and small insects.


It is in this stage that the Rhinoceros Iguanas have fully developed their behavior in defending their food sources, their territory, and the ability to blend with their environment to avoid predation with the bigger animals. As soon as they have reached their sexual maturity after 5 to 9 years from the time they were born, these reptiles begin to develop their senses for sexual responsibilities. They are now able to reproduce during the mating season and travel more in search of better habitat within the islands, and possibly, to escape from the potential predators that significantly deplete their population.

Eating Habits

Generally, Rhinoceros Iguanas are omnivores, eating a wide variety of leaves, grasses, wild fruits, and vegetables. At times, they can be seen eating sea creatures, such as dead fishes and small crabs. In their younger years, Rhinoceros Iguanas are known to practice eating on small flying and crawling insects, chewing them slowly, assuring its prey that it will not escape from the prowess of this animal. 

Its jaws and teeth are designed for chewing on plants and other vegetation. However, in need for defense, these jaws can cause powerful bites, giving its potential prey a painful experience, allowing them to run away quickly from sudden death.

Due to the restrictions of vegetation on the island, Rhinoceros Iguanas often compete with the herbivore animals, leading to their predation.

Sleeping Habits

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Rhinoceros Iguanas are known to be diurnal animals, enjoying the scorching heat of the Caribbean sun, especially during the summer. They are known to sleep at night and strictly follow the 12-hour night period. They hide in rocky shelters to avoid potential predators roaming at night and blend with the forest through the help of their skins, which effectively saves them despite their big sizes, especially with the male iguanas.

One should also remember that the place where a species lives greatly affects its way of sleeping. In the Caribbean Region where the Rhinoceros Iguana lives, the islands do not experience a winter spell at all, making the animals inhabiting it, not to be required in undergoing Brumation Cycle.

Behavior and Reproduction

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Rhinoceros Iguanas are generally timid and shy. These animals are heliothermic- they must adjust their daily activities with the availability of sunlight for them to normally move while keeping their homeostasis at the proper levels. With the required amount of radiation and light, these iguanas are only limited to live in tropical and sub-tropical regions of the world, which makes the Caribbean Island of Hispaniola an ideal and perfect spot for these reptiles. 

They are not violent with the other iguanas of the same gender, not until the Mating Season of May comes and every Male Rhinoceros Iguana is becoming aggressive in search of their partners.

The elaborate exhibition of Male Rhinoceros Iguanas to win a female’s heart consists of head bobbing, spine erection at their backs. As soon as they have captivated their targeted partner, the process of sexual reproduction begins and has to wait for 4 to 5 months before successfully laying its eggs.

Health Conditions

During their days in captivity, Rhinoceros Iguanas may experience the following illnesses:

Metabolic Bone Disease

Your Rhinoceros Iguanas may experience a serious illness where they have swollen jaws, soft jaw, and facial bones, or swollen hind legs. This is considered as Metabolic Bone Disease. This popular health problem is caused by improper nutrition by taking foods high in Phosphorus while low in Calcium or Vitamin D3. It is commonly seen among juvenile iguanas with ages 2 and below.

Despite its serious condition, one can simply help a Rhino Iguana recover from this illness by sustaining a stable source of UV-B rays in the enclosure of your animals. Apart from UV exposure, they should eat superior nutritious foods to keep their skeletal and muscular strength in stable and increasing conditions.

Mouth Rot or Stomatitis

This is one of the common sicknesses of Rhinoceros Iguanas both in captivity and in the wild, just like the other reptiles existing in both living conditions. It is the infection of their oral cavity, characterized by pus on their lips and in their mouth. If the worst possible case happens, an anole suffering from this condition may have a swollen mouth and will show difficulties in breathing.

This sickness is not a primary condition but is an underlying problem to a bigger issue such as improper nutrition just like with how MBD develops, and sudden changes with the temperatures or climate.


It is a normal condition for pet iguanas, including the Rhinoceros Iguanas, to have their internal and external parasites. However, these must not be underestimated nor ignored as they may lead to more serious illnesses with the Rhinos. Manifestations of the parasitic infestation on a Rhino include developing ticks and mites on its skin. These parasites are hard to point out as the host needs to undergo a medical examination to check on the status of its digestive tract and the other organs inside its body. Fortunately, it is not due to your household sanitation. Instead, it is because of the other iguanas, your Rhino one has interacted with before having it as a pet in your house.

If left unaided, these parasites may cause diarrhea, weight loss, and even death with your Rhino Iguana.

Preventing Illnesses

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A Rhinoceros Iguana owner must know how to keep its pet avoid acquiring any forms of illnesses which these animals usually face when living in the wilderness.


In modern times, the scarcity of natural water supply for the Rhinoceros Iguanas living in the wild has drastically depleted due to the destructive and extensive human activities, such as mining and land conversion. With this, the Rhino Iguanas are forced to travel more inland and seek for potable water streams coming from the mountains of Hispaniola.

In captivity, one must remember that the water supply should be kept steady and always clean to keep its homeostasis at good levels. Change the water regularly and avoid putting the water source near the basking lamp. The water must be cool enough to balance the body temperature of iguanas.


Strictly follow the Nutritional Intake needed by your Rhinoceros Iguana, especially on the specific plants that they must eat, such as dandelions and mustard greens, okra, bell peppers, and snap peas, pumpkin, acorn, and butternut, with fruits such as papaya, mango, kiwi, bananas, strawberries, pears, and even apples.

Providing them great access to nutritious foods will also mean a healthier iguana for you and fulfilling your tasks of taking care of them in the right way.

On top of these things, make sure that there is no substrate under the iguana’s food container, to avoid digestion problems and parasitic growth inside its body. It is highly recommended to make the food container stable from overturning or simply make it attached to the ground but can be cleaned every time.

Light and Temperature

Keeping the enclosure with the ideal light setup and temperature for your Rhinoceros Iguanas will give them higher chances of living longer lives, compared with those who still live in captivity and deals constantly with human and animal predation. Strictly observe the ideal setup to avoid any possible health conditions which may happen to your iguana if you preferred saving your electricity bill by simply switching off the lamp in a long time and keeping it one with a shorter period, than what must be done in favor to them.


Because of their required sunlight exposure, these animals badly need a consistent water supply to keep them hydrated and healthy. There are cases wherein Rhinoceros Iguanas suffer from dehydration because of the heat waves happening in Hispaniola over the years, worsened by the Global Warming, making them more vulnerable to illnesses and predation, despite their mature ages.

It is required for these reptiles to take water from time to time, without intervals, especially when kept for captivity.


Rhinoceros Iguanas are no exemption to the rule when it comes to the reptilian molting process. It is a constant process of giving them more space to grow while keeping their bodies at the shape and far from deprivation that may lead to organ problems underneath their thick and scaly skins.

The challenge in taking care of iguanas is that they shed more when they are younger and need a continuous process to allow their young bodies to grow more. There are instances that they are shedding within a year to keep their substantial growth move at a stable rate. To assist them in shedding, it is necessary to keep the moisture of their enclosure be in higher volume and mist their bodies to keep the process smoother and faster. It has been proved that the juvenile Rhinoceros Iguanas shed their skin faster in a more humid place, allowing their old skin peel with lubrication, like how the snakes need to be hydrated and humidified during their molting processes.

After shedding, one must clean the molting area to keep the old skins away from them, maintaining a clean space for the young iguanas and make them avoid eating their old skins which may carry different bacteria.


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Rhinoceros Iguanas live in the rocky forests of the Caribbean while living with a great dependency on the solar radiations produced by the scorching Hispanic sun. With this, it is proper for the Adult Rhinoceros Iguanas to have a terrarium with big space, averaging from 10 x 10 x 4 feet. 

This cage is ideal for a single adult iguana only. However, if there are more than 2 iguanas that need to live in the same cage, it is going to be best for them if you build a larger enclosure, complete with rock formations, a water trough, and some big plants or small trees for them to shelter.

Because of the space requirement it demands, some Rhino Iguana owners prefer to build an outdoor cage from them, using thick steel mesh enclosures to keep them inside while allowing them to be exposed with the real sunlight. The owners who prefer keeping their rhinos inside their homes use special lamps to keep the nutrition that each iguana receives from the solar radiation outside.

Lighting and Humidity

Three lamps need to be installed in an outdoor Iguana cage- one is for color-corrective, the other is for UVB rays, and the third is for the basking spot.

These lamps come in different wattages. Despite this requirement, one can save money by combining the UVB lamp with the basking spot, or the color corrective lamp, in case of a smaller cage. The basic role of these lamps is to provide vitamin D for your iguanas, to help them develop their muscles and bones, making your animal grow bigger and better.

When it comes to humidity, the ideal humidity inside the tank must range from 60% to 85%. Fortunately, your room humidity will work for the iguana, not requiring you to buy humidifiers anymore. In the event of the shedding process, remember that it will help if the humidity inside the room is increased by misting your reptile and keeping the water source of larger volume than the usual.


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Rhinoceros Iguanas have used to deal with hotter temperatures, and with this case, it is recommended to keep the enclosure have the average temperature ranging from 75 to 88 degrees Fahrenheit for the daytime and 65 to 75 degrees Fahrenheit during the nighttime. For better understanding, check the conversion below:

Time of the DayTemperature in FahrenheitTemperature in Celsius
Daytime81 (average)75 to 88 (range)27.2 (average)23.8 to 31.1 (range)
Nighttime70 (average)65 to 75 (average)21.1 (average)18.3 to 23.8 (range)
Basking Spot100 to 106 37 to 41

Avoid making the temperature inside its cage drop to 62 degrees Fahrenheit or 16.7 degrees Celsius or lower, as it will stress out the Iguana and create a loss of appetite and weight loss for your reptile.

Tank Bedding and Accessories

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Make your Rhinoceros Iguana comfortable in its enclosure by doing all of your best to imitate its original habitat in the Hispaniola. Use some sands and rocks to recreate its natural ground, as well as applying some moss in the ground to keep the moisture and humidity inside the cage nicely regulated. To add more leisure for your iguanas, you can include tree branches inside for it to climb and walk upon, especially that the basking spot must have its elevation to prevent too much ground heat, preventing your iguana from sleeping peacefully at night.

Taking Good Care of your Rhino

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The good side in taking care of Rhino Iguana is their intelligence and ability to socialize with us humans, once they are trained to do so. Here are some tips to take care of your iguana:

  • Live in warm places with proper lighting and access to wider spaces
  • Avoid confining your iguana in a small space to give it the right to exercise, run and bask safely, under your supervision
  • Let it drink clean and safe water
  • If your iguana is young, mist it regularly, thrice a day to sustain its successful shedding week after week or lesser than how it should go
  • Offer them the best higher spots for basking during the day
  • Regulate and keep the ideal temperature and humidity at all times
  • Give them safe foods to eat, predominantly made up of vegetables and fruits
  • Do not let male Rhino Iguana live in the same terrarium
  • Keep their eggs placed in a different tank in the time that a female iguana laid its eggs

Where to get One?

They’re in need reputation has put them to the limelight of exotic reptile animals that can be owned as pets in different households. With this, they are widely sold in legal pet shops across the United States and the other parts of Hispaniola. However, stiffer regulations are now applied to keep the endangered species maintain their population in the wild and avoid how the Navassa Island Iguana went extinct due to us humans.


Can I pet my Rhino Iguana?

There are times that a Rhino Iguana may find it uncomfortable to carry their body with your arms and accidentally scratch you with their sharp nails.

The good thing with them is that they love to be touched if placed down on the grounds and let them walk around. They enjoy the interaction in a spacious area where they find everything comfortable and safe from all predators.

Do a Rhino Iguana’s bite painful?

Yes, of course! Its lethal bite can kill all of its preys on its first bite. However, they rarely bite as they are considered gentle giants and friendly with humans, except during the mating season. 

Is Rhino Iguana poisonous?

Having mentioned about its power to bite, the good thing with the Rhino Iguanas is that, they are not poisonous. Unlike the other reptiles, they have no toxins embedded with their teeth and mouth, but the way they kill their preys are excruciating.

Can I store up to 3 Rhino Iguanas inside a cage?

Depending on the size of your cage, you can store this number of Rhino Iguanas inside a common cage. However, the size of their cage must be a room big to avoid confrontation with the other Rhino Iguanas, especially when they are hungry or when the time of breeding season comes, where all animals become aggressive and thirsty for mating.

How will I separate the newly laid eggs from a mother, Rhino Iguana?

First, catch the mother Rhino Iguana, which is highly aggressive in watching for its babies during the early stages of laying eggs. After catching the mother, gently get the eggs one by one. Avoid rotating it from its sides and keep it in a container with a warmer temperature.

Another method is to simply wait for the Mother Iguana abandon its nest and get the eggs cautiously. As mentioned, the Mother Rhino Iguanas let her babies live independently, far from how the mammals take good care of their children.

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