Green iguana

Green iguanas eat plants.

They munch leaves, flowers and fruit. Baby iguanas sometimes eat a few insects too, to help them grow.

Green iguanas are herbivores. Grown-ups eat mostly leaves, flowers and ripe fruit high in the trees. Young iguanas need more protein for growing, so they sometimes eat insects too.

Iguanas hardly chew. They use their tongues to move food and bite off pieces small enough to swallow. Sitting in the sun warms their bodies, which helps them digest the tough leaves. Iguanas also help spread the seeds of the plants they eat.

Adults are primarily folivores and frugivores, eating leaves, flowers and fruit, with occasional invertebrates or carrion; juveniles, with higher protein needs, take more insects and eggs (Animal Diversity Web).

Food is bitten into swallowable pieces with little or no chewing. Most digestion happens in a chambered hindgut (the sacculated colon), where microbes break down cellulose; hatchlings eat adult droppings, which may be how they acquire these microbes. Temperature matters: cold suppresses appetite and digestive enzymes, and active feeding happens at about 25 to 35 °C, so basking and digestion are closely linked. Iguanas also disperse seeds. Where they are invasive, the same diet becomes a problem; Britannica notes that in Florida they eat fruits and vegetables from orchards and gardens, damage landscaping and threaten native tree snails.

Iguanas love to lie in the sun.

The warm sun helps their bodies work. If danger comes near, they can jump from a branch into the water and swim away.

Like other reptiles, iguanas get their warmth from around them. In the morning their skin is darker, which soaks up sunlight; in the hot middle of the day they turn paler.

They like to rest on branches over water. If a hawk or another danger comes near, an iguana can drop into the river and swim swiftly away. Iguanas argue most over good sunny perches, and in the breeding season males guard their own patch. They talk with body language: bobbing their heads and spreading their dewlaps.

Iguanas are diurnal ectotherms, and color supports thermoregulation: darker skin early in the day absorbs heat, paler skin at midday reflects it. They bask on limbs overhanging water, and their main escape is to drop in and swim strongly or stay motionless and rely on camouflage.

Visual signals dominate communication: head bobbing, dewlap extension and color change. In the breeding season males defend territories and display to rivals; Animal Diversity Web notes that injuries are rare because rivals have room to retreat. Cold is a real limit. Britannica explains that when Florida temperatures drop below about 7 °C (45 °F), iguanas can become cold-stunned, lose their grip and fall from trees, sometimes needing days to recover.

Lots of green iguanas live in the wild.

In some places, people let pet iguanas go. There, the iguanas eat garden plants. If you see a wild iguana, watch it from a distance and do not touch.

Green iguanas are listed as Least Concern, which means the species is not thought to be at risk of dying out. In some places, though, hunting for food and catching for the pet trade have made them much rarer.

In places where pet iguanas were released or escaped, like Florida and Puerto Rico, the iguanas have become a problem. They dig burrows that can make sidewalks collapse, and they eat garden plants and native plants. If you see a wild iguana, enjoy it from a distance, don't touch it, and never let a pet reptile go outdoors.

The IUCN Red List assessed Iguana iguana as Least Concern in 2018, reflecting its very large range, though local populations have declined through hunting for meat and eggs and collection for the pet trade. Iguanas are also farmed for food and leather in some countries.

Outside the native range the picture flips. Released and escaped pets founded invasive populations; in Florida, Britannica and the state wildlife agency (FWC) report burrows that erode sidewalks, seawalls and canal banks, damage to landscaping and gardens, tree-snail remains found in iguana stomachs and the spread of Salmonella. Florida added the species to its prohibited list in 2021, encourages removal from private land and forbids releasing captured iguanas elsewhere. The species is a clear example of how the same animal can be secure at home and harmful elsewhere.