Black Spinytail Iguana and Green Iguana

​Jenna is a graduate student at the University of Florida. Currently she is studying Wildlife Ecology and Conservation while working in south Florida to manage invasive animals. Jenna primarily works with the Argentine Black and White Tegu and other invasive lizards.

​Iguanas have become one of the most common invasive reptile seen in southern Florida. You can find them in trees, crossing streets, eating the flowers in your garden... Two of the more well known species of iguanas in Florida are pictured below - the Black Spinytail Iguana (Photo by Jeff Whitlock, 2013) and the Green Iguana (Photo by Save the Prairie Society, August 3, 2017).

Black Spinytail Iguana (Ctenosaura similis)
​This species is native to southern Mexico, and was first noticed in Florida in 1978. Currently it has established its self breeding populations in Dade, Lee, and Charlotte counties in Florida. Adult males of this species can reach four feet in length, and females remain smaller. These lizzards are primarily terrestrial species, and are extremely wary of humans. When they feel threatened these iguana will retreat to their burrows for safety, however they are able to climb quite well if they are unable to safely reach their burrow (Bartlett and Bartlett 1999). 

The habitats that this iguana is able to exploit are very broad. They can be found living on coastal uplands, in exotic plant communities, low density suburban developments, agricultural fields, and areas surrounding core urban areas and small towns. Over the years this species has spread across south Florida. First thought to be established in Lee county (1980), then Collier county (1998), and finally Broward county (2002); this species was introduced due to released or escaped animals intended for the pet trade.

The distribution of Black Spinytail Iguanas in Florida, 10 February 2018.

Green Iguana (Iguana iguana)
The Green Iguana is a large lizard that is also nonnative to Florida. This species, like the Black Spinytail Iguana, was introduced through the pet trade as well. The Green iguana lives terrestrially, and can be seen on the ground and in shrubs and trees all over suburban developments, urban areas, small towns, and agricultural areas. They are excellent swimmers, can tolerate fresh and salt waters, and can remain under water for up to four hours at a time. Male Green iguanas can grow over five feet in length and weigh just under 20 lbs, while females usually do not exceed 7 lbs at full maturity.

Originating in Central America to the tropics of South America and some eastern Carribbean islands, the Green iguana was first reported in Florida in the 1960s in Hialeah, Coral Gables, and Key Biscayne. Now the popualtions spread along the Atlantic coast in Broward, Martin, Miami-Dade, Monroe, and Palm Beach Counties; along with the Gulf Coast in Collier and Lee counties.

Distribution of the Green Iguana in Florida (EDDMAPS, 10 February 2018)

Status in Their Native Ranges
Although the Green Iguana has not been formally assessed in its native range, both it and the Black Spinytail Iguana are listed as being of least concern where they originate from. This means that they are exhibiting characteristics of a healthy population that is reproductively active and not exposed to any threats which may cause them to become threatened, endangered, or extinct.

Diet and Impacts
The diet of the iguanas includes a wide variety of vegetation. They are known to eat shoots, leaves, blossoms, and fruits of plants including nickerbean, hibiscuses, garden greens, jasmine, orchids, roses, Washington fan palms, squashes, and melons. They also occasionally feed on bird eggs, carrion, insects, and tree snails.

Due to their diet, iguanas pose a threat of damage to residential and commercial landscape vegetation and are considered a nuisance animal by property owners. They are most attracted to trees with fruit and flowers, with the exception of citrus. The dig burrows, which can erode and collapse sidewalks, foundations, sea walls, berms, and canal banks. They pose a threat to native and endangered species of tree snails, as well as have the potential to spread diseases and infectious bacterium Salmonella to other reptiles and to humans through water contact or surfaces contaminated with feces.

 Iguana Removal
Iguanas can be legally removed year round with land owner permission. They are not protected by any laws except for the anti-cruelty laws. Florida Fish and Wildlife Conservation Commission (FWC) encourages the removal of Green iguanas on private land by landowners, and captured iguanas can be kept as personal pets or humanely euthanized. The iguanas cannot, however, be relocated and released at other locations.

In order to deter iguanas from your own property you can alter the habitat around our home ot humanely harass the animals until they leave. Some effective methods are: removing plants that act as attractants; filling in holes to discourage burrowing; putting wind chimes or other items in the yard to make intermittent noises; hanging CDs or other reflective material outside; and spraying the animals with water.

More Information
Workshops
​Iguana Brochure
Iguanas in the Florida Keys
​Dealing with Iguanas
Iguana Assistance for Homeowners