Nonnatives - Green Iguana

Green Iguana
(Iguana iguana)

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Adult green iguana

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Male green iguana displaying orange coloration

Description

The green iguana (Iguana iguana) is a large lizard not native to Florida. Hatchling and young green iguanas usually have bright green coloration. Adults range in color from green to brown to almost black, although usually remain predominantly green as they mature. Some adults can take on an orange or pink coloration during breeding season. Green iguanas have a row of spikes down the center of the neck, back, and upper portion of the tail, and have dark black rings on the tail. Mature male iguanas develop heavy jowls and a throat fan (or dewlap) that are much larger than those of female iguanas. Larger throat fans can make male iguanas appear bigger, repel rivals or warn predators. Female iguanas may choose to breed with male iguanas that have larger dewlaps. The throat fan can also help iguanas regulate body temperature.

Green iguanas can live on the ground, in shrubs or in trees in a variety of habitats including suburban developments, urban areas, small towns and agricultural areas. Green iguanas are excellent swimmers and tolerate both salt and freshwater. They can submerge themselves for up to 4 hours at a time.

Male green iguanas can grow to over 5 feet in length and weigh up to 17 pounds. Females reach lengths similar to those of males, but usually do not exceed 7 pounds. Females typically reach reproductive maturity at two to four years of age. Green iguanas typically mate in October through November in their native range, and nesting occurs on riverbanks, beaches and other sandy areas. Females dig egg chambers that may contain nearly 80 feet of interconnected tunnels and multiple entrances and lay clutches of anywhere from 14-76 eggs. Green iguanas can live up to 10 years in the wild and 19 years in captivity.

Diet

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Map courtesy of Ron Jeremy External Website:
Native range map of Iguana iguana

Green iguanas feed on a wide variety of vegetation, including shoots, leaves, blossoms and fruits of plants such as nickerbean, firebush, jasmine, orchids, roses, Washington fan palms, hibiscuses, garden greens, squashes and melons. Adult green iguanas can also feed on bird eggs and dead animals. Juvenile green iguanas feed on vegetation, insects and tree snails.

Native range

The native range of green iguanas extends from Central America to the tropical parts of South America and some eastern Caribbean islands.

Florida distribution

Green iguanas were first reported in Florida in the 1960s in Hialeah, Coral Gables and Key Biscayne along Miami-Dade County’s southeastern coast. Green iguana populations now stretch along the Atlantic Coast in Broward, Martin, Miami-Dade, Monroe and Palm Beach Counties and along the Gulf Coast in Collier and Lee Counties. There have also been reports as far north as Alachua, Highlands, Hillsborough, Indian River and St. Lucie Counties. However, individuals observed in more northern counties are likely escaped or released captive animals and are unlikely to establish populations, as iguanas are not cold hardy. In cleared habitats such as canal banks and vacant lots, green iguanas reside in burrows, culverts, drainage pipes and rock or debris piles. South Florida’s extensive man-made canals serve as ideal dispersal corridors to further allow iguanas to colonize new areas.

Link to map of credible sightings at IveGot1.org. External Website

Potential impacts

Green iguanas can cause damage to residential and commercial landscape vegetation, and are often considered a nuisance by property owners. Iguanas are attracted to trees with foliage or flowers, most fruits (except citrus) and almost any vegetable. Some green iguanas cause damage to infrastructure by digging burrows that erode and collapse sidewalks, foundations, seawalls, berms and canal banks. Green iguanas may also leave droppings on docks, moored boats, seawalls, porches, decks, pool platforms and inside swimming pools. Although primarily herbivores, researchers found the remains of tree snails in the stomachs of green iguanas in Bill Baggs Cape Florida State Park, suggesting that iguanas could present a threat to native and endangered species of tree snails. In Bahia Honda State Park, green iguanas have consumed nickerbean, which is a host plant of the endangered Miami Blue butterfly. As is the case with other reptiles, green iguanas can also transmit the infectious bacterium Salmonella to humans through contact with water or surfaces contaminated by their feces.

Regulatory status

Green iguanas are regulated as Class III wildlife in the State of Florida. A permit is not required to possess green iguanas as personal pets. However, a License to Possess Class III Wildlife for Exhibition or Public Sale must be obtained to possess these reptiles for commercial use and a Captive Wildlife Importation Permit is required to import this species into the state.

Technical assistance information

Can I remove iguanas from my property?

Green iguanas are not protected in Florida except by anti-cruelty laws and can be removed from private property year-round with landowner permission. The Florida Fish and Wildlife Conservation Commission (FWC) encourages removal of green iguanas from private properties by landowners. Members of the public may also remove iguanas from 22 FWC managed public lands without a license or permit under Executive Order 17-11 Adobe PDF. Captured iguanas can be kept as personal pets or can be humanely euthanized, but cannot be relocated and released at other locations in Florida. More information about humane methods of euthanasia is available from the American Veterinary Medical Association External Website. Homeowners that trap iguanas on their property can obtain euthanasia services from local exotic veterinarians, humane societies or animal control offices. For more information, view the FWC’s PowerPoint on Iguana Technical Assistance for Homeowners.

How can I deter green iguanas from frequenting my property?

If you have an iguana frequenting your area, you can take steps to deter the animal such as modifying the habitat around your home or humanely harassing the animal. Examples of effective habitat modification and harassment include:

  • Removing plants that act as attractants
  • Filling in holes to discourage burrowing
  • Hanging wind chimes or other items that make intermittent noises
  • Hanging CDs that have reflective surfaces
  • Spraying the animals with water as a deterrent

View the FWC presentation Iguana Technical Assistance for Homeowners Adobe PDF.

What if I own a pet iguana I can no longer care for?

Escaped or released pets remain a primary source of introduced species in Florida, although it is illegal to introduce nonnative species into the state. Through the FWC’s Exotic Pet Amnesty Program, pet owners who are either unable to care for their exotic pets, such as green iguanas, or who no longer wish to keep them can surrender them with no questions asked and without penalties regardless of whether those pets are kept legally or illegally. Surrendered pets are adopted to new owners who have been pre-qualified and who have any required permits. The EPAP helps reduce the number of nonnative species being released into the wild by pet owners and fosters responsible pet ownership, giving pet owners an ethical and ecologically sound alternative to releasing an exotic animal.

More Information

FWC Iguana Workshops

Green Iguana Brochure Adobe PDF

Iguanas in the Florida Keys Adobe PDF

Iguana Technical Assistance for Homeowners Adobe PDF

Dealing with Iguanas in the South Florida Landscape External Website

Exotic Pet Amnesty Program

References

Behler, J. L., & King, F. W. (1979). Audubon Society field guide to North American reptiles and amphibians. Knopf: Distributed by Random House.

Breuil, M. (2002). Histoire naturelle des amphibiens et reptiles terrestres de l'archipel guadeloupéen (Guadeloupe, Saint-Martin, Saint-Barthélémy: Basse-Terre, Grande-Terre et les îlets satellites, Marie-Galante, les Saintes, la Désirade, les îles de la Petite Terre, Saint-Martin et les îlets satellites, Saint-Barthélémy et îlets satellites). Collection patrimoines naturels.

CABI. (2017). Iguana iguana. In: Invasive Species Compendium. Wallingford, UK: CAB International. www.cabi.org/iscExternal Website

Engeman, R. M., Smith, H. T., & Constantin, B. (2005). Invasive iguanas as airstrike hazards at Luis Munoz Marin International Airport, San Juan, Puerto Rico. Journal of Aviation/Aerospace Education & Research, 14(3).

Hawaii Department of Agriculture. (2009). Iguana captured on Maui. Hawaii, USA: Hawaii Department of Agriculture. http://hawaii.gov/hdoa/news/2009-news-releases/news External Website

Jacobson, E. R. (2003). Biology, husbandry, and medicine of the Green iguana. Krieger Publishing Company.

Johnson, D.F. (2006). The Iguana Trapper. (http://www.iguanatrapper.com/).

Kern Jr, W. H. (2004). Dealing with iguanas in the South Florida landscape. Fact Sheet ENY-714, entomology and nematology, Florida cooperative extension service, institute of food and agriculture science. University of Florida, Gainesville.

Krysko, K. L., Enge, K. M., Donlan, E. M., Seitz, J. C., & Golden, E. A. (2007). Distribution, natural history, and impacts of the introduced green iguana (Iguana iguana) in Florida. Iguana, 3, 2-17.

Lazell Jr, J. D. (1973). The lizard genus Iguana in the Lesser Antilles. El género de lagartijas Iguana en las Antillas Menores. Bulletin of the Museum of Comparative Zoology., 145(1), 1-28.

Loftin, H. and E.L. Tyson. (1965). Iguanas as carrion eaters. Copeia 1965:515.

Moberly, W. R. (1968). The metabolic responses of the common iguana, Iguana iguana, to activity under restraint. Comparative Biochemistry and Physiology, 27(1), 1-20.

Rand, A. S. (1968). A nesting aggregation of iguanas. Copeia, 552-561.

Rand, A. S., & Dugan, B. (1983). Structure of complex iguana nests. Copeia, 705-711.

Rodda, G. H., & Burghardt, G. M. (1985). Iguana iguana (green iguana) terrestriality. Herpetol. Rev, 16, 112.

Townsend, J. H., Slapcinsky, J., Krysko, K. L., Donlan, E. M., & Golden, E. A. (2005). Predation of a tree snail Drymaeus multilineatus (Gastropoda: Bulimulidae) by Iguana iguana (Reptilia: Iguanidae) on Key Biscayne, Florida. Southeastern Naturalist, 4(2), 361-364.

Wiewandt, T. A. (1982). Evolution of nesting patterns in iguanine lizards. Iguanas of the world: their behavior, ecology, and conservation, 119-141.



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