It’s hot, the iguanas are afoot: Here’s what you need to know

June 21, 2019
By Marcy Shortuse

BY MARCY SHORTUSE – While we have been dealing with an iguana eradication program for many, many years, at Tuesday’s meeting it became apparent that either people haven’t been reading about the situation or just recently moved here. Because of this, and at the iguana panel’s request, we will attempt to break down the pertinent information here.

  • There are two main types of iguanas in Southwest Florida: green and spiny-tailed. The black spiny-tailed type lives in the ground, often inhabiting gopher tortoise burrows. An island man named Bumps Johnson admitted just a few years ago that a relative of his brought the iguanas from Mexico and kept them as pets, but Bumps turned them loose when their original owner moved away from home.
  • If you think we have a lot of iguanas now, you weren’t here prior to the iguana control program’s beginning. The amount once estimated by esteemed scientist Dr. Jerry Jackson was 12,000. George Cera killed 4,000 more than that in the first few years. They were so prevalent, in fact, that they were coming out of sewers and into people’s toilets, they were always fighting in the road down by South Beach (which used to be and still is a prime spot for them for some reason), and a day wouldn’t go by that you wouldn’t see one dead on the road. Almost everyone who has a home here frequently had one come in the house.
  • Spiny-tailed iguanas will eat the eggs of turtles and tortoises, birds and other iguanas. They eat anoles, salamanders and skinks. They are larger than the majority of our island animal population, which makes them an apex predator. The only threats they have are man and – when they are very small – predatory birds, dogs, raccoons, snakes and cats.
  • While some people may fill in the holes in an attempt to eradicate iguanas in their yard, filling in gopher tortoise burrows is a serious offense. Gopher tortoises are listed as a threatened species, and they cannot be taken, killed, hunted or harassed, nor can their burrows be destroyed without authorization from the Florida Fish and Wildlife Conservation Commission (FWC) or when complying with FWC-approved guidelines for specific actions which may impact gopher tortoises or their burrows. It is illegal to tamper with turtles or their nests, and that law has been fervently upheld on Gasparilla Island specifically.

Green iguanas, by the way, are found only occasionally on Gasparilla Island. They almost always live much farther south of us, as they cannot handle cold and they don’t burrow. There have been times on Sanibel Island when it was “raining iguanas” after a particularly harsh cold snap. Our iguanas snuggle up in their burrows and wait it out.

  • If you set traps on your property, you are required by Florida state law to check each trap at least once every 24 hours. Leaving any animal in a trap longer than 24 hours is a crime under Florida law. FWC law states that captured nontarget species are required to be released on site.
  • Also keep in mind that all native animals killed as part of a nuisance wildlife program must be euthanized in accordance with the AVMA guidelines for the euthanasia of animals (as per the FWC), which means injection with sodium pentobarbitol IV or IC, followed by decapitation or deep freezing. Needless to say, these methods are not recommended for private homeowners, nor are the ingredients attainable.
  • No one is allowed to discharge a firearm in a designated wildlife sanctuary (all of Gasparilla Island, in other words) without special permission (such as what our trapper has). Animal cruelty laws are very specific in this state, and other means of termination of a native species must be humane. The FWC guidelines on their website very specifically state that it is not a good idea to try to eradiate a native species from your property, as another animal will come in and take its place.

These lizards have been around, like the opossum and the alligator, since prehistoric times. They have learned to adapt and survive using every means necessary, including dramatically altering their diets and appearance. They are smart and built to survive. While you might get an iguana in a trap one time, you can be sure the other iguanas on your property will learn from the behavior a trapped iguana presents. No amount of attractive bait will entice them to enter a trap a second time.

  • One way to increase your chances of success is to pre-bait. This means you open and bait the trap, allowing an iguana to enter and exit a few times after eating his fill. After you are confident an iguana has visited the trap and found it to be a food source, set the trap for capture.

Snares set by private individuals must be ground snares, not hanging snares, to ensure the safety of other animals that might be caught (i.e., pets). Snares work well with iguanas, because they hold their heads up as they move about in order to watch for predators.

  • Snares should only be set during the day, when iguanas are active, and sprung at night to make sure nocturnal animals aren’t caught up in them.  Iguana-proofing your home and property requires a lot of diligence and some sacrifice. Seal all routes of animal entry under and around your home. Cover chimney tops with mesh. If you live in a home on stilts or with a crawl space underneath, you will need to secure those areas as well. Keep all pet food inside. Use deer or rabbit repellant spray on plants to keep iguanas from having an ideal place to live and feed. Most importantly, realize that thick, lush foliage and landscaping are a paradise for iguanas.
  • While poison may seem like an enticing possibility for killing iguanas, it was an option that was only briefly discussed by the iguana panel in years past after discussions with the U.S. Department of Agriculture. There was a very loud public outcry against it, and it was determined by researchers that more than likely, nontarget animals could very well be killed, including pets and endangered or threatened species.
  • No poisons are registered or legal for use on iguanas or any other reptiles in Florida.
  • There are certain plants that iguanas love to eat that should not be perpetuated. Preferred food sources include hibiscus, orchids, impatiens, pink pentas, roses, bougainvillea, nasturtiums, all greens (kale, broccoli, mustard, collards, sorrel, beets, lettuce, squash melons), purple queen, turf grasses, and weeds such as Spanish needle and frog fruit.

Instead of planting these, try an iguana-resistant plant such as milkweed, oleander, citrus, crotons and many other toxic, tough, thick-leaved plants.

  • Most importantly, remember that our iguanas are not nice. They bite, claw and use their tails as formidable weapons. Not only do you risk a serious injury from an iguana, you also risk a high rate of infection from a claw or tooth.

These iguanas have lasted for this long on the planet for a reason: Not many other species want to mess with them, and catching them is not as easy as you think.