Godzilla of Gasparilla

The ctenosaurs are here; and they’re taking over. When they’re done chomping through your yard, they’ll start gnawing on your electrical cables, and eventually on your house. Then, they’ll work their way inside by sneaking up through your toilet bowl. When it’s time to move on to the next house, they’ll be sure to leave behind a pungent reminder of their visit.

While this could be a trailer to a really bad horror movie, it’s not fiction. It’s all true and it all takes place right here in the U. S. of A. For residents of Gasparilla Island--an exclusive barrier island town in southwest Florida--the invasion of ctenosaurs is a reality they cope with every day.

They look like a creature straight from my nephew’s dinosaur books, and have a name to match. Ctenosaurs are also known as black spinytail iguanas--a reptile native to the southern Pacific coast of Mexico and Central America. Legend has it that a Mexican boat captain brought the iguanas to Gasparilla as pets for his children. When they grew large and confrontational, they were let go. With its comfy island climate, Florida was a place where the iguanas could not only survive, but thrive. As of December 2007 estimates, about 12,000 ctenosaurs roam the 3-square-mile sand spit called Gasparilla; they outnumber their human counterparts 10:1.

While many of the problems that the iguanas create involve property damage, they have had a huge ecological impact, as well. They’re great tree-climbers that target bird eggs and nestlings, and have the potential to wreak havoc for the endangered gopher tortoises and indigo snakes on the island. The ctenosaur problem is reminiscent of my days in Guam where the brown treesnake--another non-native invasive species--had the same predatory tendencies. The snake population there grew to about 10 million in about 70 years; and 9 of Guam’s 12 native forest birds went extinct. Gone forever. But the spinytail iguanas don’t stop at birds and eggs. They’re omnivores—they’ll eat most anything, including insulation, wiring, ornamental shrubs, and much more.

While a local ordinance offers protection for all wildlife on Gasparilla Island, frustrated residents are taking matters into their own hands. Armed with golf carts, traps, and BB guns, they are attempting to thin the herd. Because of the widespread nuisance the iguanas have created, local police have turned a blind eye to the slayings.

This year, a special "lizard tax" has been imposed for residents. The funds will bring federal biologists to the scene to try their hand at bringing the population to an acceptable level.