There are more than 30 species of iguanas, belonging to the class Reptilia. Depending on the species, iguanas inhabit a wide range of environments, from swamps and lowlands to deserts and rainforests. Iguanas are further divided into nine broader species categories: Galapagos marine iguana, Fijian iguana, Galapagos terrestrial iguana, spiny-tailed iguana, rock iguana, desert iguana, green iguana, and Kakwalas.

Quick overview

• Scientific name: Iguanidae

• Common name: Common Iguana (Green Iguana)

• Order: Squamata

• Elementary Animal Group: Reptiles

• Size: Maximum 5 to 7 feet (green iguana), minimum 5 to 39 inches (spiny-tailed iguana)

• Weight: Up to 30 pounds (Blue Iguana)

• Lifespan: Average 4 to 40 years, depending on the species

• Diet: Fruits, flowers, leaves, insects, and snails

• Habitat: Rainforest, lowland, swamp, desert

• Numbers: Approximately 13,000 Fijian iguanas per species; 3,000 to 5,000 spiny-tailed iguanas per species; 13,000 to 15,000 green iguanas per species.

• Conservation status: Least Concern (Green Iguana), Endangered (Fijian Iguana), Critically Endangered (Fijian Crested Iguana)

• Interesting fact: Marine iguanas are excellent swimmers.

describe

A portrait of an iguana sitting on a tree branch.

Iguanas are cold-blooded, egg-laying animals and among the largest lizards found in the Americas. Their size, coloration, behavior, and unique adaptations vary by species. Some iguanas, such as the Fijian spotted iguana, are bright green with white or light blue stripes, while others are darker. The most abundant and well-known iguana species is the green iguana (Iguana iguana). They average 6.6 feet in length and weigh up to 11 pounds. Their green color helps them camouflage themselves in bushes, and they have a row of spines on their bodies for defense.

Rock iguanas have long, straight tails and short, powerful limbs, which help them climb trees and limestone formations. They have a flap of skin called a dewlap in the throat area, which helps regulate temperature. Spiny-tailed iguanas are large omnivores, and the black spiny-tailed iguana is the fastest lizard, reaching speeds of up to 21 miles per hour.

Marine iguanas feed on rocks covered with algae.

Marine iguanas are black, which helps them warm their bodies after swimming in cold water. They lack gills and therefore cannot breathe underwater. However, they can hold their breath underwater for up to 45 minutes. Their flat tails help them swim like snakes, allowing them to quickly consume algae for several minutes before returning to the surface. Their long claws allow them to grip the bottom while grazing. Due to their diet and the large amounts of saltwater they consume, marine iguanas have developed the ability to sneeze excess salt through their salt glands.

Habitat and Distribution

Depending on the species, iguanas inhabit a variety of habitats, including deserts, rocky areas, swamps, rainforests, and lowlands. Green iguanas are found throughout Mexico, extending to Central America, the Caribbean islands, and southern Brazil. Iguana species inhabiting the Caribbean islands are collectively known as rock iguanas. Desert iguanas are found in the southwestern United States and Mexico, while the Galapagos Islands are home to two species of marine iguanas.

Diet and behavior

Most iguanas are herbivores, eating tender leaves, fruits, and flowers. Some feed on insects such as waxworms, while marine iguanas dive into the ocean to harvest algae from plants. Some species have bacteria in their digestive systems that allow them to ferment the plant material they eat.

Young green iguanas are omnivorous, but become almost entirely herbivorous as adults. Young green iguanas primarily eat insects and snails, while adults switch to fruits, flowers, and leaves. They have sharp teeth that can tear leaves apart. Green iguanas also live high in the tree canopy, and as they age, they inhabit even higher altitudes. Another interesting fact about iguanas is that they can detach their tails when threatened and have them regrow later.

Reproduction and offspring

Iguanas typically reach sexual maturity at 2 to 3 years of age, and depending on the species, they can lay 5 to 40 eggs per clutch. For green iguanas, males establish mating relationships with females during the rainy season and leave the treetops at the start of the dry season to fertilize the eggs.

Most iguana species dig a burrow in a sunny location, lay their eggs inside, and cover them. The ideal temperature range for incubation is 77 to 89 degrees Fahrenheit. Depending on the species, the young hatch after 65 to 115 days. After being dug out of the burrow, the newly hatched iguanas begin their lives.

Species

The Fijian crested iguana (Brachylophus vitiensis) lives on Viti Levu Island in Fiji. It is a critically endangered iguana species found on several islands in Fiji.

There are approximately 35 species of iguanas currently in existence. The most abundant species are the common iguana or green iguana (Iguana). Based on habitat and adaptation, iguanas are divided into 9 categories: Galapagos marine iguana, Fijian iguana, Galapagos terrestrial iguana, spiny-tailed iguana, rock iguana, desert iguana, green iguana, and chakwalas.

threaten

The Fijian iguana is an endangered species, with the Fijian crowned iguana listed as critically endangered. The biggest factor contributing to the decline in Fijian iguana numbers is predation by invasive species such as wildcats (Felis catus) and black rats (Rattusrattus). Furthermore, the crested iguana is also severely threatened by the rapid loss of its habitat in the dry, healthy forests of the Fiji archipelago. This habitat loss is due to deforestation, burning, and the conversion of forests into farmland.

Protection status

According to the International Union for Conservation of Nature (IUCN), the green iguana is designated as a least concerned animal. Under IUCN regulations, all species in the Fijian iguana group are listed as endangered, with the Fijian crowned iguana (Brachylophus vitiensis) listed as critically endangered.

iguanas and humans

Green iguanas are the most common pet reptiles in the United States, but many die within their first year due to their difficult care. In Central and South America, green iguanas are farmed and consumed. Their eggs are considered a delicacy and are often referred to as "chickens from the trees."