There are different varieties of iguanas in nature; they live in both tropical and subtropical forests, in the desert, or coastal areas. They are found in America from southeast Canada to central and South America, in the Galapagos Islands, some Caribbean islands. Also in Madagascar and the Fiji Islands.
The iguana family includes the largest lizards in the Americas. They are cold-blooded, oviparous (they reproduce through eggs) animals that have a great capacity to adapt to the environment. Within the family, there are very different species in size, color, and behavior. Some are very common, like the green iguana (Iguana iguana) and others are in danger of extinction, like the Fiji iguana (Brachylophus fasciatus). The variations are so great that it is difficult to recognize them as members of the same family. The marine iguanas of the Galapagos Islands are excellent swimmers and their skin is black so that they can warm up better in the sun after swimming in the cold ocean waters. On the other hand, green iguanas live on the treetops in the rainforests and others have adapted to live in the dry and hot desert environment.
Most iguanas are herbivores. They feed on fruits, flowers, and tender shoots. Some species occasionally eat silkworms or mealworms.
In the wild, females lay their eggs in holes they dig in sunny places, then cover them up and leave them alone. The temperature there is kept constant between 77 to 86ºF, enough to incubate the eggs. The hatchlings usually all hatch at the same time and make their way through the earth or sand to the surface, without the help of the parents. From then on the face several dangers, including natural predators, environmental adaptation, and poachers, which have decimated populations that were numerous in the past.
Measures to prevent this are the breeding of these animals in captivity, the regulation of hunting and trade, and the education of people living near their natural habitats. In some Caribbean islands, the greatest danger to iguanas is from cats introduced by man. The cats feed on eggs and young, thus interrupting the reproductive cycle. In these places, they have begun to collect the eggs to incubate them in safe places, raise the small lizards for a while and release them when they are big enough to protect themselves from the cats.
In some places in Central and South America, the meat of the green iguana is highly appreciated and there are large breeding grounds for it. The locals call them “gallina de Palo” (chicken tree) because they are found on trees.
In the animal kingdom, it is common for males to have more attractive colors than females, but in the case of iguanas, it is the other way around. Males have a dull green color with an orange breast, while females have a brighter green. It’s the young that have the brightest green color. However, males have erect spines on their heads that make them appear larger and more attractive to females. A male with his spines injured or with signs of bite occupies a low place in the hierarchy at mating time.