Iguanas in South Florida
Iguanas have emerged as an invasive pest species in South Florida during the last decade. At first glance, iguanas seem to fit the tropical profile, palm branches swaying in the breeze with a large, colorful exotic lizard perched atop. However, the reality is much different. Iguanas cause significant damage to foliage and landscapes, leave large droppings containing Salmonella in areas they inhabit, and destroy the food sources and habitats of some endangered species. In short order, iguanas have become a nuisance pest, and Florida Fish and Wildlife Commission actively encourages homeowners and businesses to eliminate them from your property.
There are three main species of iguana that inhabit South Florida:
- Green Iguana
- Mexican Spiny-Tailed Iguana
- Black Spiny-Tailed Iguana
- Argentine tegus
Green iguanas are the most common iguana found in Florida. They are typically green, especially when they are juvenile, but sometimes darken to dark brown or even black. During mating season, adult males may take on an orange hue. Green iguanas have a row of spikes down the center of their body and upper portion of their tails. Mature males develop large jowls and a throat fan used to woo females, warn predators, and regulate his body temperature in the winter. Green iguanas can run quickly, climb anything they desire, and are excellent swimmers. They can survive a fall from 40 feet in the air onto solid ground.
Male iguanas regularly weigh up to 17 pounds and measure over 5 feet in length; females rarely exceed 7 pounds. Green iguanas feed on young shoots of leaves, blossoms, and foliage. Iguana are primarily herbivores, but they will sometimes eat bird eggs and dead animals, and juvenile iguana will occasionally eat insects and the endangered tree snail. Iguana prefer to eat the young leaves on ornamental plants because they have higher protein concentrations and less cellulose making them easier to digest. The specific plants favored by iguana tend to be commonly used ornamentals in South Florida including:
- Garden Greens such as lettuce, mustard greens, collard greens, kale, broccoli, and beets
- Most fruits and flowers
Iguanas are prolific breeders. In the wild, green iguanas usually live about 10 years. A female begins laying eggs around 2 years old, and she typically lays between 35 and 70 eggs at a time. Iguanas have thrived in South Florida due to the warm, tropical climate, dense, lush landscapes, lack of predators, and their rapid rate of reproduction. However, they are not cold-hardy. When a rare winter blast of cold air sweeps through South Florida, meteorologists forecast includes, “cold snap with a chance of falling iguanas.” The cold weather causes iguanas to become immobilized and fall from their perch. However, this is only a temporary paralysis, when their bodies warm up, they wake up again.
Damage Caused by Iguana in South Florida
Iguanas in South Florida have caused losses and expenditures in the millions of dollars. Local governments and home-owners associations must execute emergency repairs, diverting funds from other projects. The City of West Palm Beach recently spent $1.8 million dollars repairing an already aging water dam after iguanas burrowed around the structure compounding the problem. Resorts and restaurants that promise the tropical experience must protect their foliage and shrubs, and golf courses must protect their greens and fairways. To fulfil customer’s expectations, resorts and restaurants, marinas, and beaches, must deliver the lush, tropical foliage free from iguana droppings and gigantic lizards.
- Damage to Landscaping and Crops – Iguanas are predominantly herbivores and will happily feast on the tender young shoots of flowering plants. Many South Florida homeowners and business have invested heavily in their landscaping and cannot allow the foliage to be systematically destroyed. Many commercial crops are also in danger of consumption by iguanas. Iguana eat mangoes, tomatoes, lychee, bananas, and berries.
- Damage from Iguana Burrows – Iguanas lay their eggs in underground burrows. Sometimes these burrows are up to 80 feet long. Iguanas burrows have a characteristic D shaped entry hole with a pile of sand near the entry. These burrows are often found near seawalls. Iguana burrows compromise the integrity of seawalls, foundations of buildings, sidewalks, and the canal and dam system in South Florida. These repairs are expensive and complicated.
- Iguana Droppings – In addition to residing in trees and in underground burrows, iguanas also enjoy basking in the open sunlight of a patio or deck, and docks or a moored boat. Where they sun themselves, they leave behind unsanitary and unsightly droppings. Iguanas leave fecal droppings in and around pool decks, on restaurant patios, and on the walkways of marinas. The fecal matter of iguana is known to carry Salmonella; it is a public health risk to allow these droppings to remain unfettered in such close proximity to humans.
- Damage to Homes and Buildings – Iguanas are excellent climbers and enjoy sunning themselves on barrel tile roofs common in South Florida. Their sharp claws can damage the waterproof layer under the tiles causing roof leaks and interior damage. Black Spiny-Tail Iguana prefers to live in burrows. These burrows are long and complex and may compromise your foundation. Very rarely, although it has happened, iguanas may attempt to burrow through a pipe and end up in your toilet!
- Disruptions to Native and Endangered Species – The ecological impacts of the recent South Florida iguana boom are not yet fully understood. The Florida Burrowing Owl is a “protected species of special concern.” Interactions between iguanas and the Florida Burrowing Owl have been observed with the concern being that the iguanas will aggressively force the Florida Burrowing Owl from its burrow for their own needs. Endangered tree snail remains have been identified from the contents of iguana’s stomachs. The endangered Miami Blue Butterfly may be at further risk, as iguanas are known to eat the nickerbean plant which is host to this rare butterfly.
How to Keep Iguanas Away
As a homeowner in Florida, you have a good deal of freedom and options to deal with iguanas as you see fit. Sometimes simple changes can be the highly effective.
- Never feed iguanas.
- Exclude iguanas by encircling valuable or vulnerable plants with a cage or screen. By placing sheet metal around the trunk of the tree, about 18 inches from the ground, iguanas cannot easily climb the tree. Sheet metal around dock pilings may also prevent them from climbing onto your dock. Wire barriers buried several inches into the ground may prevent digging or burrowing on your property. Some people even install electric fencing to prevent them from climbing walls.
- Deter iguanas from becoming comfortable on your property. Florida Fish and Wildlife Commission states that you may spray them with a water hose until they leave your property, make loud noises to scare them away, or hang CDs in the tree that reflect light in unusual ways.
- Habitat Modification is sometimes viewed as a more extreme method of iguana prevention, but in certain situations it may be justified. By altering your landscaping choices you can disincentivize iguanas from residing on your property. Remove thick foliage cover or rock piles where iguanas congregate, and fill vacant iguana burrows with concrete. Iguana love to eat brightly covered flowers and the tender shoots on these plants. Consider planting citrus trees or any tough, thick, waxy-leaved plant such as milkweed, pentas, or crotons.
How to Get Rid of Iguana
Florida Fish and Wildlife encourages homeowners and business owners to take action against iguanas. All species of iguana may be humanely killed or captured on private property without a permit. Iguanas are protected by the general animal cruelty laws; they must be dealt with humanely and respectfully. If you choose to trap iguanas, please know, it is illegal to relocate iguanas in Florida. The general guideline for a “humane” extermination is the animal must die immediately. Depending on your location and local restrictions, iguanas may be shot with a firearm or an air pellet gun. One deadly blow to the head is considered humane as well. You may not place a trap with a captured iguana in a freezer, and you may not attempt to bait iguanas with poison.
Only live traps and snares are legal in the state of Florida against iguanas. Traditional live traps baited with bright flowers and fruit can be very effective. The practice of pre-baiting the trap will lead to greater success. This is simply placing food inside the trap without setting the trap. This allows the iguana to get used to entering the trap for a quick bite of mango. Florida law requires you to check the trap at least every 24 hours. Be prepared with a plan once you trap an iguana. He can not be relocated; he must be humanely euthanized.
Experienced wildlife trappers can often remove iguanas efficiently and safely with a hand snare. Other times, your trapper may set a self-locking snare for the iguana. These can be placed near the burrow entry, on the seawall or walkway, or near holes under fences. These snares should only be set during the day light hours, as you are highly likely to catch a non-target animal at night. Discernment should be used when deciding where and when to set such snares. A commercial property that is open to the public should consider the safety of their customers first.
Harvesting Iguanas by Hand
On those few very cold South Florida when the iguanas are stunned and fall from the trees, communities have made great progress in reducing iguana populations. Ensuring there is a coordinated effort and a plan for the euthanasia of the iguanas, citizens and volunteers collect the fallen iguanas from the sidewalks and from the banks of canals and mangroves. This opportunity to impactfully reduce the iguana population only happens every few years.
Controlling the iguana explosion is in every Floridian’s best interest, but sometimes it is a problem best left to professionals. Nextgen Pest Solutions has experienced wildlife trappers and general house-hold pest management professionals eager to solve your problem.