Green Iguana (Iguana iguana) — identification, habitat & look-alikes

The green iguana is a big plant-eating lizard native to Central and South America and the Caribbean. In the U.S. it's an established invasive lizard in Florida and has also been introduced to Texas, Hawaii, and Puerto Rico. Adults usually reach 4–5.6 ft (1.2–1.7 m) from head to tail, and big ones can grow to about 6 ft (1.8 m).

Appearance

Appearance: Hatchlings are bright green; adults range from green to olive or brown, and breeding males can turn orange. Look for a hanging throat flap (), a large round scale on the lower jaw behind the mouth, and a row of spikes down the neck and back.

Look-alikes

Black spiny-tailed iguanaCtenosaura similis

Spiny-tailed iguanas have rings of pointed scales around the tail and lack the big round scale on the jaw. Adults are usually brown or gray with dark bands; young ones can be green, so check the tail rings.

Why they get mixed upBoth are large invasive iguanas in South Florida.

Knight anoleAnolis equestris

Knight anoles have a yellow or white stripe below the eye and on the shoulder, no big round jaw scale, and a narrower, arrow-shaped head.

Why they get mixed upBoth are big green lizards, and young iguanas are about the same size as knight anoles.

Where it lives

Typical habitats: canal banks
mangroves
suburban yards
tropical forest
Range: Native from southern Mexico to central Brazil, Paraguay, and Bolivia, plus many Caribbean islands. Established in much of central and southern Florida including the Keys, and also introduced in Texas, Hawaii, Puerto Rico, and the U.S. Virgin Islands.
Preferred conditions: In Florida they stay mostly near the coast, because cold limits how far north they can spread. Sustained temperatures of 30–40°F (-1–4°C) leave them stiff and sluggish, and they may drop out of trees during cold snaps.
Seasons: In Florida
Breeding Dec–Apr

Behavior

Diet: Mostly plants: flowers, fruits, and tender shoots, including landscape favorites like hibiscus, roses, and orchids. They tend to skip citrus and thick-leaved plants. Young iguanas eat some insects.
Activity: They dig burrows in canal banks and at the base of seawalls, which can speed up erosion and undermine structures.

Life cycle

Breeding season: In Florida, breeding runs from December through April, and hatchlings show up in summer.
Nest: Females dig a nest burrow about 1 ft (30 cm) deep and up to 3 ft (90 cm) long.
Clutch size: About 10–70 eggs
Incubation: About 10–15 weeks (2–3 months), with no parental care

Conservation

IUCN Red List: LCLeast ConcernLow risk of extinction
Status: In Florida the green iguana is an invasive species listed as Prohibited since 2021. It can't be newly kept as a pet, releasing one is illegal, and landowners may humanely remove iguanas on their own property year-round.

Culture and stories

Culture and stories: Green iguanas have long been among the most popular pet reptiles in the U.S. In Florida they were first recorded around Miami in the early 1960s, and a dealer released more than 300 in 1964.
During a cold snap in January 2020, the National Weather Service in Miami even issued an unofficial “falling iguana” alert.