English           -           Green Iguana 

Portuguese    -           Iguana Verde 

 Latin               -          Iguana iguana 

 The Green Iguana is a fairly large lizard and is a well known reptiles due to its popularity in zoos and with private reptile keepers.

Although called Green Iguanas, these animals are actually variable in colour. The adults become more uniform in colour with age, whereas the young may appear more blotchy or banded between green and brown. Colour of an individual may also vary based upon its mood, temperature, health,social status and range. Such colour alteration may aide these animals in thermoregulation. Active dominant Green Iguanas usually have a darker colour than lower-ranked Green Iguanas living the same environment. Most colour variation seen in this species is exhibited by males, and may be attributed in part to sex steroids. Six to eight weeks prior to and during courtship, males may acquire a bright orange or gold hue, although coloration is still related to dominance status. Mature females, for the most part, retain their green colouring. Other distinguishing features of this species include a pendulous dewlap under the throat, a dorsal crest made up of dermal spines that run from the mid neck to the tail base, and a long tapering tail. The dewlap is more developed in adult males than females. Extensions of the hyoid bones stiffen and support the leading edge of this structure, which is used in territorial defence or when the animal is frightened. This fleshy structure also serves in heat absorption and dissipation when it is extended. The laterally situated eyes are protected mainly by a immovable eyelid and freely mobile lower eyelid. On the dorsal midline of the skull behind the eyes is a parietal eye. This sense organ, although not a true “eye,” serves as a meter for solar energy, and aids in the maturation of sex organs, thyroid gland, and endocrine glands. The visual effect of this “eye” is mostly limited to the detection of predatory shadows from above. The scales or plates on the head are larger and more irregular than the scales on the rest of the body. Below the tympanum there is a large rounded scale called the subtympanic plate. They can reach up to 2 metres in length and weigh up to 5 kgs. They can live up to 20 years.

Green Iguanas, occur throughout Central and South America, from Mexico, south to the Tropic of Capricorn in Paraguay and southeast Brazil. This large lizard also inhabits many islands throughout the Caribbean region and the coastal eastern Pacific, and has been introduced into southern Florida and Hawaii. Green Iguanas most commonly inhabit tropical forest close to water, from sea level up to an altitude of 1,000 metres, although they avoid areas of deep forest where the sun cannot reach the ground. They are arboreal lizards that live high in trees. Juveniles establish areas lower in the canopies while older mature iguanas reside higher up. This tree dwelling habit allows them to bask in the sun, rarely coming down except when females dig burrows to lay eggs. They can also adjust well to a more open area. No matter where they inhabit, they prefer to have water around as they are excellent swimmers and will dive beneath the water to avoid predators.

Green Iguanas are primarily herbivorous so they mainly eat leaves, flowers, and some fruits. They require a high amount of dietary protein in their first two to three years for adequately fast growth. During this time period, young iguanas may consume insects and spiders.

Most Green Iguanas reach sexual maturity between three and four years of age. Green Iguanas tend to breed in the dry season, ensuring the young hatch in the wet season when food is more readily available. Mating appears to be polygynandrous. Courtship occurs within a defined territory where more than one female may be present. Conflicts between males are not uncommon. Courtship behaviour of males includes head bobbing, extending and retraction of the dewlap, and nuzzling or biting a female’s neck. Dominant males may also mark rocks, branches, and females with a waxy pheromone-containing substance secreted from their femoral pores. During mating, the male approaches the female and climbs on her back, straddling her. To restrain his mate, he grips her shoulder skin with his teeth, sometimes causing wounds.  Female iguanas can save sperm for several years, allowing them to fertilise eggs at a much later date. Green Iguanas are oviparous.  Females lay their eggs about 65 days after mating. Eggs are deposited into the nest which is a burrow in the ground. The nests can be from 45 cm to more than a meter deep, and may be shared with other females if nesting areas are limited. Egg Incubation is from 90 to 120 days. Temperature has to range from 29.4 to 32.7 degrees celsius in the nest for the eggs to survive. The hatchlings pip the egg open using a special egg tooth, called the caruncle, that falls off shortly after hatching. Absorbed yolk provides most of the nourishment for the first week or two of an Green Iguanas life. The young Green Iguanas are independent from birth. The females give no parental protection after egg laying, apart from defending the burrow during excavation.

Green Iguana’s are not considered a conservation risk at the moment. although throughout Latin America, the Green Iguana is hunted for its beautiful, commercially-valuable skin, prized flesh, and eggs. It is one of the neotropical reptiles most frequently hunted for food, to feed families or to sell, and are either shot or captured by dogs. They are also captured live; newly-hatched iguanas may be exported for the pet trade, while captured female Green Iguanas may be cut open to extract the eggs and then released. These females subsequently die due to their wounds. This level of exploitation, in combination with deforestation, has decimated populations in some parts of its range.

Photos of the Green Iguana were taken at Parque das Aves - Foz do Iguacu - Parana.