Green Iguana (Iguana iguana)

ReptileLizardHerbivore

Overview

The green iguana (Iguana iguana) is a large, mostly herbivorous, tree-dwelling lizard native to the tropical regions of the Americas. It is among the largest lizards in its range and is one of the most widely recognized iguanas, known for its long body, crested back, prominent throat fan, and tapering whip-like tail. Despite its name, the species is not always green: depending on region, age, and season, individuals can appear greenish, bluish, orange, reddish-brown, or nearly black.

Green iguanas spend much of their lives in the forest canopy near rivers and other water, basking in the sun and feeding on leaves, flowers, and fruit. They are agile climbers and capable swimmers, using the tail to propel themselves through water. Beyond their native range, the species has also been introduced and become established in some areas outside the Americas and in parts of the United States, including South Florida, where free-living populations now occur.

This profile describes the green iguana as a wild animal in its natural and introduced settings. The species is widely kept and traded in captivity, but this page is not a pet-care guide and does not offer keeping, handling, or husbandry advice. Anyone with questions about a specific animal or a local wildlife situation should contact qualified professionals or local wildlife authorities.

Taxonomy and animal group

The green iguana is a reptile in the order Squamata and the family Iguanidae, the iguanas and their close relatives. Its scientific name is Iguana iguana, and it is the type species of the genus Iguana. The classification of iguanas in the Caribbean has been actively studied, and some populations once treated simply as green iguanas have been described in recent taxonomic work as distinct forms, such as the Saban black iguana (Iguana melanoderma) and the southern Lesser Antillean iguana (Iguana insularis); taxonomic authorities differ on whether to rank these as full species or as subspecies of Iguana iguana. Because iguana taxonomy continues to be revised, the boundaries between Iguana iguana and its relatives are best confirmed against current scientific sources rather than treated as fixed.

Appearance and recognition

The green iguana is a robust, long-bodied lizard. Adults commonly reach roughly 1.2 to 1.7 m (about 4 to 5.6 ft) in total length including the tail, and most weigh in the range of about 4 to 6 kg, though a few large males can be heavier. A row of soft spines, taller in males, runs along the back and tail to form a dorsal crest, and a flap of skin called the dewlap hangs beneath the throat, used in display and in regulating body temperature. The long tail can make up much of the animal's length and may be shed and regrown if it is grabbed. On top of the head sits a pale, light-sensitive structure known as the parietal or "third" eye, which detects changes in light and movement. Coloration is highly variable across the species' range, spanning shades of green, blue, orange, reddish-brown, and near-black, and is not a reliable single field mark.

Habitat & Range

Green iguanas are primarily arboreal animals of warm, low-lying tropical environments, including rainforests and other forested areas, and they are often found near rivers, streams, or other water. Young animals tend to occupy lower vegetation while larger adults favor higher branches in the canopy. The species' native range extends across parts of Central and South America, broadly from Mexico southward into Paraguay and southeastern Brazil, and includes parts of the Caribbean. Introduced and established populations also occur in some areas outside this native range, including parts of South Florida and certain islands. Ranges shift over time and vary by region, so this is a general description rather than a complete or precise range map.

Diet

The green iguana is mostly herbivorous, and adults feed largely on leaves, along with flowers, fruit, and growing shoots from a wide variety of plants. Its leaf-shaped, serrated teeth are suited to shredding plant material, and it relies on gut microbes to break down this fibrous, plant-based diet. Young iguanas have been reported to consume some animal matter, such as insects, and to acquire helpful gut microflora early in life; older animals are predominantly leaf-eaters. Wild green iguanas have occasionally been observed taking other items, such as eggs or small amounts of animal matter, but the species is best understood as a plant-eater overall.

Behavior

Green iguanas are active by day and spend much of their time basking in the sun to warm their bodies, which as ectotherms they cannot heat internally. They are skilled climbers and strong swimmers, moving through water with side-to-side strokes of the tail, and they can drop from considerable heights in trees and land without apparent harm. When startled, an iguana may freeze, flee into vegetation or water, or display defensively by extending its dewlap, bobbing its head, hissing, and lashing its tail. In cooler conditions the species becomes sluggish; in places like Florida, unusually cold spells can leave iguanas temporarily immobilized, and individuals have been reported falling from trees during such events before recovering as temperatures rise.

As a large, abundant plant-eater, the green iguana plays a role in tropical forest ecosystems, including helping to disperse seeds from the fruit it eats. Females lay clutches of eggs, sometimes in communal nesting areas, and provide no care after the eggs are laid beyond defending the nest site; hatchlings emerge after an incubation period and may remain in loose family groups early in life. Eggs, juveniles, and adults serve as food for a wide range of predators, including birds of prey and other vertebrates, so the species forms part of the food web both as a consumer of plants and as prey. In some areas the green iguana has been observed nesting near larger reptiles such as crocodilians.

Human Interaction & Conservation

The green iguana is a calm, plant-eating lizard rather than a pet, and wild or free-living individuals are best observed from a respectful distance without feeding, chasing, or attempting to touch them. The species is one of the most heavily traded reptiles internationally and is also hunted for food in parts of its native range, where its meat and eggs have long been used. In some regions outside its native range, established green iguana populations are managed as an introduced-species issue; questions about such situations, or about any animal that appears injured or out of place, should be directed to local wildlife authorities or qualified professionals rather than handled personally. This page offers no handling, capture, removal, or keeping instructions.

More photos of the green iguana