An iguana invasion: What to do?

What turned a sleepy island retreat for millionaires and billionaires into a palm-shaded battleground where residents with BB guns patrol in golf carts?

A friend turned enemy, is the short answer.

After some kids released three iguanas by the island lighthouse nearly 30 years ago, the black spiny-tailed iguana, as well as a few green iguanas, has thrived – and thrived – here on Gasparilla Island, growing fat and lazy as they've descended Australian pines and banyan trees to be hand-fed by tourists and homeowners.

But many residents say island life has been too good to the 30,000 iguanas living on the three-square-mile spit of sand in southwest Florida. "They've turned into monsters," says resident Paul Belcher.

Today, amid a controversy over herpetology ethics and the rights of the cold-blooded, islanders say they have only one option left: Eradicate their mascot-turned-monster.

"They used to advertise them in tourist brochures, and now all of a sudden it's 'Kill them all,' " says Mark Flowers, a lizard expert in Hollywood, Fla. But he agrees that "when they're crawling in your walls when you're trying to sleep at night, you've got a problem."

Some residents have taken to shooting them off fences with BB guns during golf-cart patrols. Resident Len Tatko chases them off his neighbor's pool enclosure. He'd rather not say what became of two lizards he caught in a Hav-A-Heart trap. The lizards, he says, undermine foundations with their burrows, eat turtle eggs, and nest in attics. They also eat lots of expensive landscaping, chomping on everything from hibiscus to habaneros.

"They're pests," says Mr. Tatko. "They're no different than rats and cockroaches."

This "day of the iguana" has become a hot topic even off the island, especially the order from the county that, because of worries about spreading disease, no lizard would leave the island alive. Last week, a special "lizard tax" committee hired a mainland trapper to go after the island's most wanted, offering a $20 bounty per dead lizard brought in. Gasparilla Island residents will pay for the service through a new levy the county approved in March.

That decision has put Gasparilla Island – a secluded retreat for many wealthy families, including the Bushes and the DuPonts – into the sights of animal rights activists, while begging the question: What do you do with thousands of captured "iggys," many of which don't take kindly to captivity?

There aren't many good options, says Kevin Enge, Florida's top authority on nonnative species. For its part, the state euthanizes feral lizards that its wildlife biologists capture. At up to five feet long, black spiny-tailed iguanas, the majority of the ones on Gasparilla, do not make good pets, though there are reports that the meat can sell for as much as $14 a pound in New York City. "They're a nasty handful of wild lizard," says Mr. Enge.

Island trappers known as the Iguana Busters stepped into the fray last month when they agreed to be filmed by the "Today" show euthanizing an iguana by freezing it. They received 124 threats to their lives and property, including bomb threats, unless they quit. It had an effect.

Now the Busters vow to trap and sell iguanas to exporters through lizard collector and herpetologist George Ward, south Florida's own "iguana hunter." Mr. Ward says he has a market for the animals, and argues that a sustainable harvest of iguanas could be a boost to the economy and would ensure that many of them would be sold as pets or to zoos.

"We've offered a way to catch them and dispose of them where we keep them alive, but now all we need is acceptance and understanding" from the island community, he says. So far, the "no-kill" idea isn't flying.

Thanks to its subtropical climate and thriving pet trade, Florida has twice as many nonindigenous lizards and snakes as native ones. More problematic than iguanas are two other lizards: the Nile monitor, which has invaded the canals of Cape Coral, and the Argentine black and white tegu, which has formed a colony in Polk County. The Cuban tree frog (which, fortuitously, is a favorite snack of the Nile monitor) produces bullying tadpoles that force out native species.

The big picture, however, is that most of the newcomers occupy "empty niches" in Florida's ecology, says Enge, the state biologist. In other words, they're moving in with the Joneses – or, in this case, the DuPonts.

"They're using habitat that most of our native species don't," says Enge. "The verdict's not quite in on spiny-tail iguanas, but I think they're more of a public problem than a wildlife problem."