Green iguanas, a prominent sight across many parts of Florida, are a non-native species whose widespread presence has become a significant environmental and economic concern. These large lizards, often recognized by their vibrant green coloration, have established substantial populations, particularly in the southern regions of the state. Their adaptability allows them to thrive in various habitats, from urban landscapes to natural areas, posing challenges to Florida’s ecosystems and infrastructure.
How They Became Established in Florida
Green iguanas are originally native to Central and South America, as well as some eastern Caribbean islands, where they naturally inhabit tropical and subtropical environments. Their introduction to Florida primarily stems from the exotic pet trade, gaining popularity in the 1960s and 1970s. Many individuals, often unprepared for the reptiles’ eventual large size and long lifespan, either experienced accidental escapes or intentionally released their pets into the wild.
Florida’s climate proved highly suitable for these reptiles, offering warm temperatures, ample vegetation for food, and a notable absence of their natural predators. This favorable environment allowed the released iguanas to not only survive but also reproduce rapidly and establish breeding populations. These introductions led to their widespread distribution, particularly along the Atlantic and Gulf Coasts.
Environmental and Ecological Impacts
The presence of green iguanas in Florida has led to various negative environmental and ecological consequences. As primarily herbivorous animals, their diet consists of a wide range of plants, including leaves, blossoms, and fruits. This extensive foraging directly impacts native plant species, with documented cases of them consuming threatened and endangered flora. For instance, they have been observed eating nickerbean, a host plant for the endangered Miami blue butterfly, and defoliating native trees, including mangroves.
Green iguanas also compete with native wildlife for food resources and suitable habitats. They can displace native species by occupying burrows and nesting areas, such as those used by Florida’s burrowing owls and gopher tortoises. Although primarily plant-eaters, adult iguanas may occasionally consume bird eggs, posing a potential threat to native bird populations.
Damage to Property and Public Health Implications
Beyond their ecological effects, green iguanas cause considerable damage to human property and pose public health concerns. Their burrowing habits are particularly destructive, undermining sidewalks, seawalls, foundations, and canal banks, potentially leading to costly structural repairs. They also consume ornamental landscaping, garden plants like hibiscus and roses, and agricultural crops such as melons and squash, causing significant financial losses for homeowners and businesses.
The reptiles leave behind large amounts of droppings on docks, seawalls, porches, and even in swimming pools, which is unsightly and can create odor issues. Green iguanas are known carriers of Salmonella bacteria in their intestinal tracts. Humans can contract salmonellosis through direct or indirect contact with contaminated surfaces, water, or their feces, leading to gastrointestinal illness. Children, the elderly, and immunocompromised individuals face a higher risk of severe infection from this bacterium.
Management and Control Efforts
Addressing the escalating green iguana population in Florida involves various management and control strategies. State agencies, local governments, and property owners are encouraged to participate in removal efforts, as iguanas are not protected in Florida except by anti-cruelty laws. Methods include trapping, humane removal, and habitat modification to make areas less appealing to iguanas. This can involve removing attractive plants, filling in burrows, and installing barriers like sheet metal guards on trees and seawalls.
Public education campaigns play a role in informing residents about the impacts of green iguanas and responsible practices, such as not releasing unwanted pets into the wild. The Florida Fish and Wildlife Conservation Commission (FWC) encourages property owners to humanely remove iguanas and provides resources, including information on professional trappers. Despite these efforts, the rapid reproduction rate of female iguanas, who can lay anywhere from 14 to 76 eggs per clutch, and their widespread distribution make complete eradication a formidable and ongoing challenge.