An iguana is a large lizard with scaly skin, a long tail, sharp claws, and a row of spines running from its neck down its back. Most people recognize green iguanas by their distinctive face, loose throat skin called a dewlap, and green or brown coloring. However, iguanas can also appear gray, olive, or orange depending on their age and other factors.
TL;DR: An iguana is a large lizard identified by its long tail, row of dorsal spines, dewlap, strong claws, and distinctive large cheek scale, with coloring that can range from green to gray, brown, or orange. Adult green iguanas can grow more than 5 feet long, with the tail making up as much as three-quarters of their total length. Color alone isn’t a reliable way to identify an iguana, since body shape, facial features, and tail structure, including the large circular scale behind the jaw, are more consistent identifiers.
Key Takeaways
- Mature male green iguanas can develop bright orange coloring during breeding condition.
- Iguanas benefit from natural camouflage but don’t rapidly change their skin patterns the way a chameleon does.
- Green iguanas have a large round scale behind the jaw that similar-looking lizards, like the knight anole, lack.
- The Black Spiny-Tailed Iguana has rings of sharp, pointed scales on its tail, unlike the relatively smooth tail of a green iguana.
- Iguanas can transmit Salmonella bacteria and may cause harm through bites, scratches, or powerful tail whips.
How to Identify an Iguana
The easiest way to identify an iguana is by its long tail, spiny back, and distinctive head. The green iguana (Iguana iguana), also called the common iguana, is one of the most recognizable iguana species and is frequently encountered in Florida.
A typical description of an iguana includes the following physical characteristics:
- Long tail: A muscular tail that can account for most of its total body length.
- Dorsal spines: A row of pointed, spike-like scales extending along the neck, back, and part of the tail.
- Dewlap: A loose flap of skin hanging beneath the throat.
- Scaly skin: Small, overlapping scales covering the body.
- Strong claws: Long toes with sharp claws that help the animal climb trees and other surfaces.
- Large cheek scale: A prominent circular scale located behind the jaw.
These characteristics of an iguana make it easier to distinguish from smaller lizards commonly found around homes.
According to the University of Florida IFAS green iguana identification guide, green iguanas retain these distinguishing features regardless of their coloration.
What Colors Can Iguanas Be?
Iguanas can be green, gray, brown, olive, or orange. Although green is the color most commonly associated with iguanas, their appearance varies with age, species, temperature, and breeding condition.
Common color variations include:
- Green iguanas: Juveniles are typically bright green, while adults may have lighter or duller green coloring.
- Gray iguanas: Some adult green iguanas develop a brownish-gray appearance, particularly as they mature.
- Brown iguanas: Adults may have brown or olive-colored scales that help them blend into their surroundings.
- Orange iguanas: Mature male green iguanas can develop bright orange coloring during breeding condition.
A gray iguana is not necessarily a separate species. Green iguanas can naturally become brownish-gray while retaining their characteristic back spines, dewlap, and large cheek scale.
Color alone is not enough to identify an iguana accurately. Body shape, facial features, and tail structure are often more reliable.
Do Iguanas Camouflage?
Yes, iguanas can benefit from camouflage because their natural colors help them blend into vegetation, tree branches, and surrounding environments.
Green juveniles can be difficult to spot among leaves, while brown and gray adults may blend into tree trunks, rocks, or dry vegetation.
However, iguanas do not rapidly change their skin patterns to match any background like a chameleon might. Their coloration can vary with factors such as temperature, age, and breeding condition.
For example, green iguanas may appear darker during cooler weather, helping them absorb warmth from sunlight.
Camouflage helps iguanas avoid detection, but their long tails and distinctive body shapes can still make them recognizable.
Iguana Face, Neck, and Anatomy
An iguana’s face and neck contain some of its most recognizable identification features. Understanding basic iguana anatomy can help distinguish green iguanas from other large lizards.
Iguana Face and Neck Features
The iguana face has a broad, somewhat rounded head, prominent eyes, and distinctive scales.
Important features include:
- Subtympanic scale: A large circular scale behind the jaw, particularly noticeable on green iguanas.
- Dewlap: Loose skin beneath the lower jaw used in visual communication and displays.
- Ear openings: Visible openings on either side of the head, behind the eyes.
- Head scales: Numerous scales covering the face and jaw.
The iguana neck also has a row of pointed spines extending toward the back. These spines are usually more pronounced in mature males.
Although both males and females have dewlaps, adult males often develop larger heads and more prominent jowls.
Iguana Body, Spines, and Tail
An iguana lizard has a robust body supported by four relatively short but powerful legs.
Its long toes and curved claws provide a firm grip when climbing branches, fences, and other surfaces.
The dorsal spines are another distinguishing feature. They form a visible ridge along the animal’s back, making its silhouette recognizable even from a distance.
An iguana’s tail is long and muscular. Besides helping with balance, it can be used defensively when the animal feels threatened.
Together, these anatomical features provide a more reliable way to identify iguanas than color alone.
How Big Is an Iguana?
Adult green iguanas can grow more than 5 feet long, including their tails. Large males may exceed 6 feet, while females can reach just over 5 feet.
Their tails make up a substantial portion of their overall length, sometimes accounting for as much as three-quarters of it.
Size also varies depending on species, sex, and age. Juvenile iguanas are considerably smaller, while mature males typically develop heavier bodies and more prominent head features.
If you encounter a large lizard with a long tail, dorsal spines, and a hanging dewlap, it may be a green iguana.
What Do Baby Iguanas Look Like?
Baby iguanas generally resemble miniature adults, but they are smaller, slimmer, and often much brighter green.
Juvenile green iguanas typically have:
- Bright green skin
- Slender bodies and relatively large-looking heads
- Long, thin tails
- Smaller dorsal spines
- Less prominent jowls and dewlaps
As iguanas mature, their bodies become larger and more muscular. Their coloring may shift toward olive, brown, or gray, while their spines and other distinguishing features become more noticeable.
A young green iguana can sometimes resemble other green lizards, particularly the knight anole found in South Florida.
One useful distinction is that green iguanas have a large round scale behind the jaw, while knight anoles lack this feature.
Common Types of Iguanas and How to Tell Them Apart
Not every wild iguana looks identical. Different species have distinct colors, sizes, and anatomical features.
The following are three recognizable types:
Green Iguana (Iguana iguana)
The common iguana has a long tail, prominent dewlap, large cheek scale, and a row of dorsal spines. Despite its name, adults may appear green, brown, gray, or orange.
Black Spiny-Tailed Iguana (Ctenosaura similis)
This species is generally brown or gray as an adult, often with darker bands. Its tail has rings of sharp, pointed scales, distinguishing it from the relatively smooth tail of a green iguana.
Marine Iguana (Amblyrhynchus cristatus)
Native to the Galápagos Islands, marine iguanas generally have dark, rough-looking scales, blunt snouts, and flattened tails adapted for swimming.
For Florida homeowners, the most relevant distinction is usually between green iguanas and spiny-tailed iguanas.
The University of Florida’s nonnative reptile identification guide provides additional information for identifying reptiles encountered in South Florida.
Need Help With Iguanas Around Your Property?
Identifying an iguana is the first step toward understanding whether it could become a problem around your home. In Florida, iguanas may damage landscaping or create burrows around residential properties.
Learn more about iguana problems in Florida or explore Nextgen Pest Solutions’ professional iguana removal services if iguanas are causing problems on your property.
