Iguana – Understanding The Species, Their Features And Habitats

These fascinating reptiles have captured the imagination of generations, with their dragon-like appearance and intriguing behaviours. Scientifically known as Iguana, they belong to the genus ‘Iguana‘ within the larger ‘Iguanidae‘ family. This family is a vast and varied group, with the Green Iguana (Iguana iguana) and the Lesser Antillean Iguana (Iguana delicatissima) being the two primary species within the Iguana genus.

Of the 9 Iguanidae genus, 8 of them are native to the Americas, particularly around the warm, tropical areas of Central America, South America and the Caribbean. Species within the genus Brachylophus are the only Iguanidae that are native to land outside of the America, originating from the islands of Fiji and Tonga.

These creatures have roamed our planet for millions of years, with their ancestors leaving traces in the fossil record.

Appearance & Characteristics of the Iguana

Iguanas can range in size, but most species showcase a series of dorsal spines that run from the base of their necks to the tips of their long, whip-like tails. Their skin can vary in color, from vibrant greens to muted browns, helping them camouflage within their environments. The dewlap, a flap of skin beneath their chin, is another distinctive feature, aiding in thermoregulation and communication.

Their robust, stocky build, combined with sharp claws, makes them adept climbers, ready to scale trees or rocks in their habitats.

In both the Green and the Lesser Antilles Iguanas, the tail makes up most of their overall length and plays a large role in their lives. They use it not only for balance, but in some cases to aid with swimming and often as a primary method of defence.

How Many Iguana Species Are There?

While the term ‘Iguana’ might bring to mind a single type of lizard, the reality is more diverse. There are two primary species: the Green Iguana and the Lesser Antillean Iguana. These are the two true Iguana species from the genus ‘Iguana‘.

However, the Iguanidae family, to which the Iguana genus belongs, encompasses various genera, each with its unique species. I have created a table showing all the species within the different Iguanidae genus at the bottom of this post. This diversity showcases the evolutionary adaptability and resilience of these reptiles over the ages.

Distribution – Location and Habitat

Iguanas are sun-seekers, predominantly found in the Americas. Their range extends from the Southwestern United States, through the heart of Central America, the Caribbean islands, and deep into South America to the North of Argentina.

While many species are native to the Americas, human activities have introduced some, like the Green Iguana, to places like the Pacific Islands, Fiji, and even Japan. However, not all iguanas hail from the Americas. Some unique species, like the Fijian iguanas, are native to the islands of Fiji.

The Green Iguana is popular in the pet trade due to its striking appearance. However, their care can be challenging due to their size, dietary needs, and the specific environmental conditions they require. As a result, many are released into the wild, leading to invasive populations in areas outside their native range. A prime example of this is in Florida, where the species is now seen as invasive.

The Lifestyle & Behaviour of the Iguana

Iguanas are creatures of habit. They love basking under the sun, absorbing its warmth to regulate their body temperature. Their daily routines often involve sunbathing, foraging, and interacting with other iguanas. Their placid nature and intriguing appearance contribute to the green iguana being the most widely sold reptile in the pet trade.

While many species are arboreal, preferring the treetops, others are more terrestrial or even semi-aquatic. Social behaviors, like head-bobbing and dewlap extensions, are common communication methods among iguanas, especially during mating seasons.

Green Iguanas have special adaptions with their sight that give them great vision in some respects. They are capable of seeing in the Ultra Violet wavelengths, and can use this talent when basking in the sun to ensure they are absorbing enough energy and Vitamin D. They can see movement over long distances in good light. However, the fall off from having some of these exceptional traits, is that they have very poor vision in low light conditions.

Diet & Nutrition of the Iguana

While they might look fierce, most iguanas are gentle herbivores. Their diet primarily consists of leaves, flowers, and fruits. This is the case for both the Green and the Lesser Antillean Iguana. Depending on their habitat, they might also munch on more specific vegetation types or occasionally indulge in insects or eggs. Sometimes this is by accident, when these insects or eggs are on the leaves that the reptile is eating.

Their herbivorous nature plays a crucial role in their ecosystems, aiding in seed dispersal and vegetation control.

Predators & Threats to The Iguana

Life in the wild isn’t easy, and iguanas have their fair share of challenges. Natural predators, such as large birds, snakes and big cats can pose threats. The threats do vary by location but in the tropical regions of South America for example, boa constrictors, jaguar, ocelot and anacondas are four examples of the big predators these lizards face in the wild. Hawks and eagles are also large enough to take them on from the sky.

The biggest threat to the Lesser Antillean Iguana, has actually been the introduction of the Green Iguana to its habitat. This has introduced a direct competitor to their territory for both food and vital resources. It has also resulted in cross breeding between the two which has been recognised as one of the major contributors in the Lesser Antillean Iguanas declining population.

Additionally, human-induced challenges, like habitat destruction, hunting, and the pet trade, have significantly impacted iguana populations.

Iguana Reproduction

Iguanas are oviparous, laying eggs after a mating ritual that involves displays of strength and vibrant colors. Females will lay their eggs once per year in a synchronized nesting period, during the dry season. A clutch can number usually between 20 – 70 eggs, and are laid over around a 2 month period. Once the female lays her eggs, usually in burrows or protected areas, there’s minimal parental involvement.

In some populations, females have been observed sharing a nest if there are few suitable sites available. Eggs will develop for around 10 – 15 weeks (70 – 110 days) depending on environmental factors, such as temperature. They will hatch in the wet season, and when they do, they look like tiny little replicas of the adult females, in both shape and colour.

While quite rare in the reptile world, juvenile Iguana will stay in family groups for around the first year of their lives. With Green Iguanas, males are even known to protect females and this is a behaviour no other reptilian displays, making them quite unique.

Lifespan of the Iguana

From hatching from an egg to reaching the end of their life, iguanas go through various life stages. Hatchlings are vulnerable, relying on camouflage and hiding to evade predators. As they grow, they face challenges, from finding food to establishing territories.

The young will stay close to family for around the first year, and they will grow considerably in that time. At hatching, they weigh as little as 15 grams, and by the time they reach three years old they can weigh as much as 2 lbs.

Green Iguanas can weigh as much as 9 lbs (4 kg) for a male, on average with some exceptional males reaching up to 18 lbs (8 kg) in maturity. They may become sexually mature between 3 and 4 years of age. Females will reach about two thirds of this size. Lesser Antilles Iguana, are naturally smaller, by about a third in size again.

Across Iguana species, they can live for an average of 15 – 20 years, both in captivity and the wild. There are some exceptional cases where captive specimens have lived for much longer, but this is the average. The Lesser Antillean Iguana has a generational life expectancy of between 11 – 14 years.

Population and Conservation

Iguana populations vary across species and regions. While some thrive, others are on the brink of extinction due to various threats. The Green Iguana is listed as a species of ‘Least Concern’, but the Lesser Antilles Iguana is listed as ‘Critically Endangered’ on the IUCN Red List. The latest assessment for this species was in 2018 and the population remains in decline.

Conservation efforts for the Lesser Antilles Iguana is ongoing, and following some successes in Zoos across America, the efforts have been expanded over the last decade to incorporate Zoos across Europe too. This species is protected from trade, but the Green Iguana is traded widely – it is the most widely traded reptile in the pet trade.

Do Iguana Make Good Pets?

Iguanas, with their unique appearance and behaviours, might seem like exciting pets. However, they have specific care requirements. They need spacious enclosures, equipment to maintain and regulate temperature, such as a heat lamp and possibly a mat. They need plenty ventilation and an environment that they can be safe in when removed from their terrarium/enclosure. They have a specific diet that they need to maintain good nutrition and they need regular health check-ups.

Their long lifespan also means a long-term commitment. Potential owners should research and understand their needs thoroughly. If you are comfortable with the level of care and thought you need to put into ownership, or if you have good experience with exotic pets, then Iguanas can make excellent pets.

5 Fun Iguana Facts for Kids

• Iguanas have a special ‘third eye’ on top of their heads that helps them sense light and movement.
• If threatened, iguanas can detach their tails to escape. But that’s not all, they can grow it back!
• Their long tails aren’t just for show, iguanas use them as whips to fend off predators.
• Iguanas have sharp vision for a reptile, allowing them to see a spectrum of colors, including ultraviolet light.
• The Marine Iguana from the Galápagos Islands is the only iguana that swims in the ocean, munching on underwater algae.

Iguanidae Family Overview

The Iguanidae family includes not just the familiar iguanas but also chuckwallas and some prehistoric relatives. This family boasts several genera, each teeming with unique species. The genus Iguana is just one part of this extensive family, representing a specific subset of these fascinating lizards.

Here is a table detailing the full range of genus in the family of Iguanidae to which the Iguana belong.