Many Problems

As the feral iguana population continues to increase and expand in Florida, more residences, communities, businesses, public parks, and botanical gardens face the inevitable consequences. Initially most people seem to enjoy seeing the iguanas, but before long the problems caused by these nuisance exotic lizards result in a change of heart for most.

A large feral common green iguana poised for escape at Lake Ida Park in Delray Beach, FL.

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Once a few iguanas become established in an area they begin reproducing at a rapid pace due to a lack of predators in Florida. This prolific trait is indicative of the major role these lizards serve in the food chain within their native habitat. As such, in just a couple of years the adult (i.e., sexually mature) population will number in the hundreds. Soon their multitudes begin to alter the natural order of life as indigenous lizard-eating birds such as ibises and egrets no longer frequent the overpopulated areas.

A native Florida bird preparing to eat an adult curly-tailed lizard.

Unlike feral iguanas, Northern Curly-tailed Lizards (Leiocephalus carinatus) were purposefully introduced in Florida to help control sugarcane insect pests.

Unfortunately, a newly hatched “iglet” is larger than a full-grown curly- tailed lizard, making young feral iguanas unlikely victims of Florida’s lizard-eating birds of prey.

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Eventually an intrusion into residential areas takes place from a nearby canal, pond, lake, or the intra-coastal waterway, as the large adult iguanas are forced to look for new sources of food. In seemingly no time at all the iguanas are everywhere: on top of homes and businesses; in streets, parking lots and sidewalks; on decks, docks and boats; in pools and jacuzzis; in flower beds, shrubs, hedges, and trees.

Recently these reptilian beasts have been spotted well north of Palm Beach County, though it is currently unknown if successful breeding is taking place in those areas. The slightly colder winter temperatures keep the northern progression in check, serving as a deterrent to adults and posing a freezing threat to juveniles.

To make matters worse, South Florida is plagued with a “super” breed of iguanas. Thanks to the countless landscaped areas sporting hibiscus, bouganvilia, impatiens, caladium, etc., the diet enjoyed by iguanas here is far superior to that of their native cousins in Mexico and Central and South America. The result is a strain of iguanas which produce superior eggs which hatch superior young which grow into superior adults, all in areas where there are too few predators, if any. The situation could not be more unbalanced.

In the rare case where a bird of prey does target a hatchling iguana the odds greatly favor the lizard. In addition to being “superior” offspring, even a “normal” iguana can outrun all other lizards in Florida, native or otherwise, and can climb higher and faster, jump longer from higher perches, and use even water to escape. As if those advantages were not enough, iguanas have an underdeveloped “third eye” on top of their head which detects the shadow of a predatory bird, giving the iguana an unneeded head-start.

This is why feral iguanas have become so widespread and overwhelming in South Florida. When the first iguana is spotted in an area it is a sign of an extremely problematic and virtually unstoppable plague.

These nuisance exotic lizards consume expensive landscape plants on a daily basis, and undermine sidewalks, roadways, seawalls, pools, and other structures by digging numerous large burrows.

Two large iguana burrows on the C-15 canal in Palm Beach County which are undermining a service road used by the South Florida Water Management District (SFWMD) to access a spillway vital for flood control.

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Close up of intact burrow.	Close up of collapsed burrow.
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Remember Hurricanes Charlie, Francis and Jeanne? How could we ever forget? Feral green iguanas love the protection provided by the fenced in spillways that serve as flood control for all of South Florida’s canals. If the spillways cannot be maintained regularly then the flood control facilities are in jeopardy of not functioning properly, maybe not at all.

Erosion caused by iguana burrow...	...on bank of C-15 in Boca Raton, FL.
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Erosion caused by iguana burrow...	...on bank of C-15 in Delray Beach, FL.
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Though less commonplace than damage, the danger posed by these animals include injury to people, maiming of pets and possible exposure to salmonella bacteria (a cause of food poisoning) which can kill infants and the elderly. Some examples of harm caused by pet iguanas can be found in Animal Protection Institute’s list of Captive Reptile Incidents. Here is a subset of that list:

Those stories represent real-world incidents involving “pet” iguanas which were accustomed to being around or even handled by people. As you can imagine, feral iguanas are just as dangerous—even more so!

Finally, if you feel capable of taking matters into your own hands then consider a few solutions, otherwise consider your best option. Regardless of the case, be forewarned: