When frightened by a predator, green iguanas will attempt to flee, and if near a body of water, they dive into it and swim away. If cornered by a threat, the green iguana will extend and display the dewlapunder its neck, stiffen and puff up its body, hiss, and bob its head at the aggressor. If threat persists the iguana can lash with its tail, bite and use its claws in defense. The wounded are more inclined to fight than uninjured prey.
Green iguanas use “head bobs” and dewlaps in a variety of ways in social interactions, such as greeting another iguana or to court a possible mate. The frequency and number of head bobs have particular meanings to other iguanas.
In the wild
The native range of the green iguana extends from southern Mexico to central Brazil, Dominican Republic, Paraguay, and Bolivia and the Caribbean; specifically Grenada, Curaçao, Trinidad and Tobago,St. Lucia, St. Vincent, and Útila. They have been introduced to Grand Cayman, Puerto Rico, Texas,Florida, Hawaii, and the United States Virgin Islands; and colonised the island of Anguilla in 1995 after being washed ashore following a hurricane. Though the species is not native to Martinique, a small wild colony of released or escaped green iguanas endures at historic Fort Saint Louis.
Green Iguanas are primarily herbivores, with captives feeding on leaves such as turnip greens, mustard greens, dandelion greens, flowers, fruit, and growing shoots of upwards of 100 different species of plant. In Panama one of the green iguana’s favorite foods is wild plum, Spondias mombin.
Although they will consume a wide variety of foods if offered, green iguanas are naturally herbivorous and require a precise ratio of minerals (2 to 1 calcium to phosphorus) in their diet. It is important for captive iguanas to have a variety of leafy greens along with fruits and vegetables such as turnip greens, collards, butternut squash, acorn squash, mango,and parsnip. Juvenile iguanas often eat feces from adults in order to acquire the essential microflora to digest their low-quality and hard to process vegetarian only diet.