“Green iguanas can swim and remain underwater for up to 30 minutes when escaping predators.”
Green iguanas are large tree-dwelling lizards native to tropical America. They browse leaves, flowers, and fruit high in the canopy, bask to regulate body temperature, and dive into water when a fast escape from predators is needed.
By An Nguyen · Published · Updated
Measured against the 176 species profiled on this site. Each figure is converted to one unit system from the published range on the page, so the ranks are computed, not quoted.
| Measure | This species | Rank here | Exceeds |
|---|---|---|---|
| Body mass | 9 kg | #100 of 176#9 of 15 Reptilia | 43% |
| Body length | 1.8 m | #56 of 176#7 of 15 Reptilia | 69% |
| Top speed | 34 km/h | #55 of 75#1 of 5 Reptilia | 27% |
| Lifespan in the wild | 15 yr | #91 of 169#10 of 14 Reptilia | 40% |
Closest in body mass
Ranks use the upper end of each published adult range, so they compare typical large adults rather than records, and metrics with no published number are left out rather than estimated. The full table is downloadable from the species dataset, and any two species can be put side by side in the comparison tool.
Browse photographs of green iguana across habitat, behavior, anatomy, and life stages.
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Core article
A closer look at habitat, diet, behavior, reproduction, and conservation.
The green iguana (Iguana iguana) is a large, tree-dwelling herbivore native to tropical America. It spends much of the day high in the canopy, feeding on leaves, flowers, fruit, and young shoots and basking to warm up. Long toes and curved claws grip bark, and a muscular tail helps it swim and doubles as a weapon — threatened in a tree above water, an iguana may simply drop from the canopy and swim away.
Green iguanas are large reptiles with clear sexual dimorphism: mature males are bigger, often more colorful, and carry more pronounced dorsal spines and jowls. Adults usually run 4 to 6 feet in total length — the tail up to two-thirds of it, and some males near 6.5 feet — and weigh 9 to 20 pounds. Color varies with age, place, and sex, from bright-green juveniles to olive, gray-brown, orange, or blue adults, with dominant males brightening in the breeding season. A row of flexible keratin spines runs down the back and tail, the dewlap under the chin (rich in blood vessels) serves thermoregulation, display, and courtship, and the eyes give color and ultraviolet vision. On top of the skull sits a parietal "third eye" — it can't form images but detects light, shadow, and the movement of aerial predators. It belongs to the family Iguanidae, and its claws, arboreal build, and plant diet set it apart from insect-eating lizards.
The green iguana's native range runs from northern Mexico through Central America into South America — Colombia, Ecuador, Peru, Brazil — plus Caribbean islands like Curaçao and parts of the Lesser Antilles. It inhabits tropical forest, cloud forest, and coastal shrubland, usually near water, and is primarily arboreal, favouring trees that overhang slow rivers, oxbow lakes, and mangrove swamps — places that offer basking sites, foliage, and an instant escape route into the water below.
Unlike most lizards, the green iguana is primarily herbivorous, eating mainly leaves, flowers, fruit, and young shoots. Leaves are full of cellulose that vertebrate enzymes can't break down, so the iguana relies on an elongated hindgut that works as a fermentation chamber, where symbiotic microbes digest the plant fibre — a process that runs better when the animal is warm, which is why iguanas often bask in the morning before feeding. Serrated teeth shear leaves from stems, and much of the animal's water comes from foliage and fruit rather than drinking.
Green iguanas may bask near one another but don't form stable groups, and mature males can be strongly territorial, especially in the breeding season. A dominant male holds a large tree with good basking and access to females, meeting a rival by compressing his body to look bigger, extending his dewlap, stiffening his legs, and head-bobbing rapidly, escalating to tail strikes, biting, and wrestling if the intruder won't leave. Facing a bird or climbing snake, an iguana may freeze in the foliage, then — if detected — drop 40 feet or more into water, folding its legs and swimming with the tail, able to stay submerged up to 30 minutes. On land the tail, claws, and teeth defend it, and a tail gripped by a predator can break at a fracture plane to let the iguana escape, later regrowing a shorter replacement.
Reproduction follows the wet and dry seasons — mating in the dry season, eggs hatching near the start of the wet season when new foliage appears. After mating the female descends to find soft, sun-exposed soil and digs a burrow over a meter deep, lays 20 to 70 leathery eggs, covers the nest, and returns to the canopy with no further care. Ambient heat incubates the eggs for about 90 to 120 days, and hatchlings cut out with an egg tooth on the snout, often staying together in low vegetation before climbing higher as they grow. Juvenile mortality is high, but those that mature can live 10 to 15 years in the wild.
The green iguana is Least Concern with a stable global trend — a broad native range and large clutches cushion local declines — but local populations can still fall. In parts of Central and South America iguanas are hunted for meat (called "gallina de palo," chicken of the trees) and their eggs collected, and sustained harvest can cut the number of breeding females, while deforestation removes canopy habitat and the pet trade mixes captive breeding with illegal collection. Outside its native range, introduced populations in Florida, Hawaii, and Puerto Rico damage vegetation and compete with native species, so management differs by region — habitat and harvest controls at home, removal or containment where the iguana is invasive.
Kingdom
Animalia
Phylum
Chordata
Class
Order
Squamata
Family
Iguanidae
Genus
Iguana
Species
I. iguana
Green iguanas can swim and remain underwater for up to 30 minutes when escaping predators.
The parietal eye on top of the head detects changes in light and shadow, including movement from birds overhead.
If a predator catches an iguana by its tail, the tail can break off, and a shorter replacement can grow later.
Green iguanas can survive falls of up to 40 feet (12 meters) from the canopy.
Although they are called green iguanas, they can actually be blue, orange, brown, or even purple depending on where they live.
They are almost strictly herbivores, eating leaves, flowers, and fruit, and get all the water they need from their food.
Select a question to reveal the answer.
Green iguanas live in the warm tropical forests, rainforests, and savannas of Central and South America, spending most of their time in the treetops near water.
Green iguanas are herbivores, meaning they eat plants. Their diet consists of leaves, flowers, fruits, and young plant shoots.
The flap of skin under the chin, called a dewlap, helps with display, communication, and temperature control.
Yes. Green iguanas are strong swimmers and may dive into water to escape predators.
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