Iguanas, Growing Beach Concern

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Like dinosaurs from a bygone era, iguanas are taking to the streets of Southwest Florida and soaking up the sun. With no natural predators, iguanas are wreaking havoc on our Florida ecosystem as their population booms. Bill Veach, the Chair of the Marine Resources Task Force (MRTF) of the Town of Fort Myers Beach, explained that their committee is examining the growing iguana problem in our community.

The most common species of iguana found in Florida is the invasive Green Iguana that are usually green, but can take on other hues throughout the year, including orange and pink. Veach said that dominant male iguanas can take on an almost black coloring as well. Female iguanas can reach five feet in length and weigh roughly seven pounds, while male ones can grow even longer and reach up to seventeen pounds. With a long row of spikes down their backs and large throat fans, iguanas truly look like something right out of Jurassic Park!

The Green Iguana is an herbivore and prefers to eat a variety of plants including Nickerbeans, garden greens, squash and ornamental plants. Iguanas eat a diet as colorful as they are, Veach reported, with a preference for bright flowers such as hibiscus and orchids.

Iguanas are an invasive species that causes harm to our environment because they are not native. Invasive species upset the balance of the ecosystem by breaking apart the food chain and taking valuable resources away from animals that should live in Florida. Veach said that Green Iguanas may have come as stowaways on boats, but people release them as well from their homes when they realize they can no longer care for or they lose interest in them as pets. Iguanas began to arrive in Florida during the 1960s when first documented on the East Coast. As an invasive species, the Green Iguana has no natural predators, with virtually unlimited food and habitat resources explaining their population explosion. Iguanas use the Florida ecosystem to their advantage, with canals as a means of uninterrupted travel and culverts and retention ponds as possible nesting areas to further their spread.

While unique and colorful, iguanas pose a threat to Florida’s ecosystem. They dig burrows to live and lay eggs, with these burrows causing costly damage to infrastructure including walls, sidewalks, building foundations and sea walls. Some of these burrows are undetectable from the surface, as they are typically covered to protect eggs, but below the surface they can cause the collapse of architecture that is crucial to humans.

While causing infrastructure harm, iguanas can be a nuisance to Floridians. Iguanas leave droppings on every possible surface including pool decks and sidewalks. They eat ornamental and garden flowers, such as roses, jasmine and Washington Palms, making them a nuisance to home and business owners. Iguanas can block roads, sidewalks and large public gathering areas, increasing travel times or prohibiting people from carrying on with their everyday lives. Known for submerging themselves for up to four hours at a time and being fantastic swimmers, iguanas can become an annoyance to property owners who find themselves with one relaxing in their swimming pool!

Green Iguanas pose a threat to the survival of many species for which Florida is famous. Though iguanas are typically herbivores, they eat the endangered species of tree snails in Miami. Veach explained that iguanas can evict native Burrowing Owls from their underground nests. In the Florida Keys, Green Iguanas eat Nickerbeans, the plant that provides a home for the native and endangered Miami Blue Butterfly.

Raining Iguanas

Most disconcerting of all is that iguanas have been documented to fall from trees as the weather gets colder, in a “rain of iguanas.” They are cold blooded and require temperatures above 40 degrees to continue to move about, hunt and swim. Caught off guard, iguanas spending the night in trees become stiff and enter into a “stupor.” The iguanas then lose their balance and fall from tall heights. When they do, iguanas can appear to be dead, as they typically have closed eyes and lay dormant. Be aware, however, they are usually not dead; just warming up before they are on the move again.

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Green Iguana, illustrating that not all Green iguanas are green. Photo courtesy of FWC.

Homeowners should not move or touch the iguanas, even if they appear to be dead, as they can become aggressive and bite. While some iguanas survive these cold snaps, long periods of cold temperatures can help reduce iguana populations.

Controlling the population of iguanas in Florida takes a group effort from all citizens. Iguanas may be humanely killed on private property or captured, or you can hire professional wildlife trappers if you have a persistent iguana problem. Less drastic steps are filling iguana holes on your property, and hanging items that make noises, such as wind chimes. If you or someone you know has a pet iguana that they can no longer take care of, participate in the Exotic Pet Amnesty Program that allows pet owners to surrender any exotic animals with no questions asked. If you want to take part, please call 888-IVE-GOT1. Never release pet iguanas into the ecosystem.

The Florida Fish & Wildlife Conservation Commission offers an online presentation on “Technical Assistance for Homeowners” dealing with iguanas at bit.ly/iguanatips

Bill concluded with a Fun Fact: While never trying it himself, iguana tail meat is apparently delicious, so much so that in their native countries of South and Central America, over consumption is turning the tail on the iguanas, endangering them!

 

by Ariel Joel, Liaison
Florida Gulf Coast University, LKSP