- Scientific Name: Iguana iguana
- Status in the Wild: Endangered
- Habitat: Rainforests, Tropical Dry Forests
- Diet: Herbivore
The largest lizard species in Central America, the adult green iguana (Iguana iguana) can reach six feet in length and weigh up to twelve pounds. The species is known for its long, whip-like tail that accounts for more than half its total length. Like many lizards, green iguanas have evolved a defense mechanism where they can drop their tails if caught by a predator. Although stressful to the animal, the tail regenerates without permanent damage to the iguana.read more close
Mature green iguanas range in color from grayish-green to a dull, reddish hue while juveniles are bright green in color. Adult males have a special flap of skin called the dewlap dangling from their chin. By extending the dewlap they can appear larger in order to impressive females, or to frighten potential predators like hawks. Males also have long, soft spines that run their length of their bodies; tattered spines indicate a male with a low position in the mating hierarchy.
Green iguanas are diurnal and arboreal, meaning that they are active during the day and live in trees. Adults are almost exclusively herbivorous, dining on leaves, flowers, fruits, and the occasional small vertebrate or insect. Iguanas are skilled swimmers, and it is not uncommon for them to be in deep water or far from shore, sometimes even swimming out into the ocean.
The green iguana inhabits a large area, naturally occurring from Mexico into the Caribbean islands and down to Brazil. The species was introduced in southern Florida, where it is now considered feral (domestic-turned-wild). In Costa Rica, the green iguana is found along the Pacific and Caribbean Coasts, as well as in north-central Costa Rica. Visitors will have good luck spotting these large lizards near Arenal, Tortuguero, around the Osa Peninsula, Manuel Antonio, and along Guanacaste's Gold Coast.
Green iguanas live in lowland rainforests, both deep within vegetation and along the forest edge, where ground cover is less dense. The species is also common in lowland dry forests. Green iguanas are mostly solitary, and are usually found near water. They tend to live in the forest canopy, approximately 65-100 feet above the ground, and are capable of surviving a 50-foot fall unscathed. During cool, wet weather, green iguanas often climb down from the treetops in search of warmth.
In Costa Rica, mature males establish territorial limits in October, shortly before mating season begins. Males defend their territory using physical displays of superiority; in an iguana wrestling match, both males circle while hissing and lashing their tails, until they finally engage in physical contact. To the winner go the spoils – the territory and its females.
Each mating territory is home to four mature females. Male iguanas are polygynous, courting all four females throughout the mating season. Courtship generally lasts one month before copulation, and entails extension of the dewlap, head bobbing, and color changes due to sex hormones. Two weeks prior to mating, the male will bond to a specific female.
Mating takes place during the first six weeks of the dry season, generally beginning in mid-November. Pregnant females lay their eggs in deep nests built a foot below the surface. Communal nesting is not uncommon. Egg clutches contain 20-71 eggs, and incubate for 65-115 days; hatching occurs between April and June. Newborn iguanas measure 2.75-3.15 inches in length, and spend their early weeks basking in the sun by day and moving into low-hanging tree branches at night. Juvenile green iguanas are not solitary, often banding into groups of 10-20 at night. They reach sexual maturity at three years of age.
Status in the Wild:
Green iguanas are considered endangered in Costa Rica, and may not be traded commercially. Scientists must obtain special permits from Costa Rican government agencies to collect specimens. Though it was once common practice, today it is illegal to kill and eat wild green iguanas. Several green iguana conservation projects exist in Costa Rica; the Pro Iguana Verde Foundation is perhaps the most well known. Founded by Dr. Dagmar Werner, the foundation, located in Orotina (near Puntarenas) works with local farmers to educate the public and create buffer zones – a combination of open areas, trees, and brush – to protect the green iguana’s habitat. More than 80,000 green iguanas were raised and released into the wild during the foundation’s first five years.