Story *
A young green iguana (Iguana iguana) resting in a small tree looks very much like a “typical” lizard—slender, cryptically colored, and equally at home in scrub, forest edge, gardens, or riverside vegetation. At this stage of life, their small size and insect-heavy diet allow them to occupy a wide variety of habitats with relative safety. They can scurry up saplings or vanish into undergrowth when threatened, blending into environments that would be perilous for their bulkier adult counterparts. Juveniles, in many ways, behave like generalist lizards, flexible in where they live and how they evade predators.
As iguanas grow, however, size brings new dangers. Adults, sometimes exceeding two meters in length, are too conspicuous and heavy to rely on camouflage or low vegetation for safety. Large cats such as jaguars and ocelots, as well as raptors and terrestrial carnivores, readily prey on iguanas when given the chance. To survive, adults retreat to a narrower ecological niche—thin branches high in the canopy and limbs that extend over water. These precarious perches give them the advantage of escape routes that most predators cannot follow. A startled adult will often dive headlong into a river or lagoon, swimming to safety with powerful strokes of its tail. This shift from generalist youth to habitat-specialist adult is one of the striking transitions in their life history.
Geographically, the green iguana is native to Central and South America, ranging from Mexico to southern Brazil and Paraguay, including much of the Amazon Basin. But humans have extended its range far beyond these borders. Released or escaped pets have established breeding populations in Florida, Hawaii, Puerto Rico, and many Caribbean islands, where they are now considered invasive. In parts of their introduced range, they can cause ecological disruption by competing with native species and consuming ornamental or agricultural plants. The iguana in this photo, asleep and vulnerable in a sapling, represents not just a stage in the growth of an individual but also the adaptability of a species that has expanded from its Amazonian homeland to become one of the most widely recognized lizards in the world.