The south Florida population of iguanas is rebounding robustly from a major Mother Nature push back at the turn of the decade. Cold spells in 2008 and 2010 killed off a lot of them and for several years I hardly saw any (Go here and here to see video of cold-zapped iguanas falling out of trees).
Why are they here? The pet trade mostly. They’re nicely disposable when they wear out their welcome; just let it go, it’ll survive. Here they have plenty to eat, lots of places to live unchallenged and, most years, a great climate. They get up to five feet long (including tail), live 15 to 20 years in the wild, breed more than once a year, and, with sharp teeth and claws, have few predators once they become adults. The only thing that slows them down is an unusually long and cold winter. Cold puts them in a stupor for a while and can kill them. In the West Palm Beach area, I am about at their northernmost Florida range. Native to Central and South America, there are feral populations now in South Florida (first reported in Miami in 1964), Hawaii and the Rio Grande Valley of Texas.
What to do about them? Basically just get along and hope for cold spells once in a while I guess (and don’t grow hibiscus, which they dearly love). They skitter fast, well…like lizards, swim like fish and climb trees like squirrels. They mostly live in tunnels along the banks of waterways. They’re edible, but there’s not enough of a market for them in the US to put a dent in the supply. Here are some recipes, by the way.
They mainly stay out of my way, living down on the dock and only rarely venturing past the chain link fence into the yard. They scatter when approached, and flee when I bat a stick around in the rafters of the boathouse prior to using the lift.
Garlic oil or neem oil is said to repel them. I haven’t tried either. A commercial repellant called Iguana Rid is a mix of neem oil (pressed from the fruits and seeds of the neem, an evergreen tree endemic to the Indian subcontinent), red pepper and garlic.
Like their smaller cousins, they’ll drop a tail if necessary and regrow it. I have not seen that happen. And, to explain why it’s hard to sneak up on them, they have not only excellent vision in their standard two eyes, but possess a ‘third eye,’ a white photosensory organ on the top of their heads. This primitive feature has only a rudimentary retina and lens and cannot form images, but is sensitive to changes in light and dark and can detect movement.
On the other hand…I don’t have to shovel snow here!