Orlando too cool for iguanas — for now

Central Florida isn’t quite warm enough for an invasion of iguanas such as the one in South Florida, where an emerging approach to controlling their numbers is roasting them for dinner.

But there are reasons why Central Floridians should keep their eyes on the lizards.

Orlando’s weather could become more like Miami’s, while green iguanas could evolve with reproduction to tolerate somewhat cooler conditions.

“In theory, both of those are possible, and you might even predict they would happen,” said Coleman Sheehy, collection manager for herpetology at the Florida Museum in Gainesville. “We’ll just have to see what actually happens.”

Green iguanas are native to low-elevation lands from Mexico through Central America and to several countries of South America.

First reported in Florida 50

years ago, they have invaded nearly a dozen counties along the state’s Gulf and Atlantic coasts, but none farther north than Lake Okeechobee.

With males growing to 5 feet and 17 pounds, they are dining on gardens and landscaping, and defecating in pools and on sidewalks.

The lizards are vulnerable to being stunned by cooler weather, rendering them rigid and prone to dropping from trees.

That happens when the thermometer settles merely into the 50s and 40s.

“Depending on the temperature and the amount of time the cold temperature is sustained, iguanas may only be cold-stunned and not killed,” said Jamie Rager of the Florida Fish and Wildlife Conservation Commission. “Extreme cold or sustained cold temperatures may kill iguanas, but those conditions are rare in South Florida.”

Miami winters don’t bring the cold snaps experienced in Orlando.

Since 2000, the South Florida city has not had a freezing night. A regional neighbor, West Palm Beach, has had two freezes in that period.

By comparison, Orlando has recorded 31 days of 32 degrees or lower since 2000.

But the planet, the nation and Florida are warming up.

Many temperature records set in Central Florida in recent years have been for the warmest overnight low.

While they last, cooler winters may be Central Florida’s best friend in repelling South Florida’s green iguanas and more fearsome reptiles, such as Burmese pythons and the particularly vicious monitor lizards.

“Those are two big predators you really don’t want around,” said Sheehy of the Florida Museum.

MIKE STOCKER/STAFF PHOTOGRAPHER A green iguana suns itself in Dania Beach, in Broward County. Since arriving in South Florida about 50 years ago, the reptiles have proliferated. They are in about a dozen counties, but none north of Lake Okeechobee.

MIKE STOCKER/STAFF PHOTOGRAPHER Iguanas congregate on the seawall in the Three Islands neighborhood of Hallandale Beach. Summer heat brings them out in larger numbers.