Green iguanas are a noticeable presence in Florida, particularly in the southern regions. These large lizards, often seen basking in the sun, are not naturally found in the state’s diverse ecosystems. Their proliferation has raised questions about their classification and the role they play within Florida’s environment. This article details their origins, significant impacts on natural habitats and human infrastructure, and ongoing management efforts.
The Invasive Status of Iguanas
Green iguanas are classified as an invasive species in Florida, defined as a non-native organism that causes or is likely to cause harm to the environment, economy, or human health. They meet this definition due to their rapid reproduction rates, adaptability, and widespread negative effects.
The Green Iguana (Iguana iguana) is native to Central and South America and parts of the Caribbean. Females lay clutches of 14 to 76 eggs, reaching reproductive maturity at two to four years of age. Their ability to thrive in Florida’s climate, coupled with a lack of natural predators, allows them to outcompete native species and disrupt local ecosystems.
How Iguanas Arrived in Florida
Green iguanas arrived in Florida primarily through the exotic pet trade. They were first documented in the Miami area in the early 1960s, with intentional releases by pet dealers contributing to their establishment. Many were initially brought to Florida as pets, valued for their vibrant appearance and manageable size when young. However, as these reptiles matured, they often became too large or aggressive for owners to handle, leading to accidental escapes or deliberate releases into the wild. Florida’s subtropical climate provides an ideal environment, mimicking their native habitats. Warm temperatures, abundant vegetation, and numerous waterways facilitate their survival and rapid proliferation, allowing robust breeding populations to establish.
Impacts on Florida’s Ecosystems and Infrastructure
Green iguanas inflict extensive damage on Florida’s natural ecosystems and human infrastructure. Ecologically, their voracious herbivorous diet impacts native plant species, including endangered ones like nickerbean, a host plant for the endangered Miami blue butterfly. They consume ornamental plants, fruits, and vegetables, threatening agricultural crops and residential landscaping. While primarily herbivores, adult iguanas also consume bird eggs and hatchlings, potentially reducing native bird populations. They may also compete with native burrowing species, such as gopher tortoises and burrowing owls, for shelter.
Iguanas cause considerable infrastructure damage through their extensive burrowing. They dig complex tunnel systems that can undermine sidewalks, foundations, seawalls, dikes, and canal banks, leading to erosion and structural collapse. For example, repairs to an iguana-damaged dam in West Palm Beach cost $1.8 million, highlighting the significant financial burden these activities impose. Their presence near power lines and transformers can also result in power outages. Additionally, iguanas deposit large amounts of droppings on docks, boats, and around pools, creating unsightly messes and potential public health concerns. These droppings can carry Salmonella bacteria, transmittable to humans through contaminated surfaces or water.
Management and Control Efforts
Florida authorities, including the Florida Fish and Wildlife Conservation Commission (FWC), actively manage and control green iguana populations. Green iguanas are not protected in Florida, except by anti-cruelty laws, meaning they can be humanely removed from private property year-round without a permit or hunting license. The FWC encourages landowners to remove iguanas from their properties, and removal is also permitted on many public lands in South Florida without a license.
Control methods vary but emphasize humane approaches. Trapping, often with live traps baited with fruits, is a common technique, and professional wildlife removal services are available to assist property owners. Homeowners can deter iguanas by modifying landscapes, such as removing attractant plants, filling burrows, and installing barriers like fencing or sheet metal around tree trunks to prevent climbing. Captured iguanas must be humanely euthanized and not relocated or released elsewhere in Florida, as this is illegal and contributes to the species’ spread. The FWC advises against using poisons or steel traps, emphasizing humane killing methods if euthanasia is necessary.