MIAMI, FL — There was a time when Floridians could count on the occasional burst of wintry weather to knock iguanas from the trees and deliver a death knell to the exotic reptiles that have made their way from distant lands into Sunshine State parks and even the backyards of unsuspecting homeowners. Those days may soon be coming to an end.

“There’s going to be many, many incapacitated and dead iguanas throughout South Florida, but not nearly as many as we had when the initial iguanas were here — when they first started showing up and we had the big cold fronts,” nationally known animal expert Ron Magill of Zoo Miami told Patch Wednesday.

Magill made the observation following a night of temperatures that plunged into the upper 30s and low 40s around Miami. See also Burrowing Iguanas Cause A $1.8M Dam Problem In West Palm Beach

The unseasonable temperatures prompted the National Weather Service to issue an unusual advisory Tuesday night, warning South Florida residents not to be surprised if they see iguanas falling from the trees overnight.

“I haven’t personally seen any drop yet this morning,” Magill said.

Zoo Miami took precautions to keep its usual residents safe from the cold, though not for the iguanas that meander through the grounds, he said. “I did find one on the ground that was totally incapacitated.”

“The thing is now — as each year goes by — these iguanas learn to burrow themselves during the cold,” Magill said. “The ones that have not learned that are the ones that die. Then they don’t pass that gene on to the next generation.”

Unlike bufo toads, which secrete a poison that is deadly to dogs, the fallen iguanas do not pose a specific health threat to man’s best friend other than with their claws — and the fact that they can theoretically pass on salmonella, which is typical of reptiles.

While some people don’t mind the green invaders — with their rows of exotic spikes down the center of their neck, back and upper portion of the tail — others are happy to see them drop from the trees when the temperature falls below 40.

The Florida Fish and Wildlife Conservation Commission said male iguanas can grow to 5 feet in length and weigh up to 17 pounds.

The agency warns that iguanas can cause “considerable damage to infrastructure, including seawalls and sidewalks.” They are not protected in Florida except by anti-cruelty laws, so it is legal to kill them humanely on private property.

Magill — who has appeared on NBC’s “Today Show,” ABC’s “Good Morning America,” “CBS This Morning,” “NBC Nightly News” and even CBS’ “The Late Show with David Letterman” — also had a disturbing observation regarding the state’s invasive Burmese pythons.

They don’t seem be affected by the cold nearly as much as they once were either, Magill said of the pythons, which have been known to grow as long as 18 feet and tip the scales at more than 100 pounds in Florida.

“A lot of them are adapting, and they burrow themselves into deep burrows or into the water, where that water temperature is always warm enough to get them through the snap,” Magill said.

Much like the green iguanas that fall from the trees, the pythons are learning how to survive a cold snap, making them even more of a threat to Florida’s native wildlife.

“I don’t know if it’s a matter of intelligence,” Magill said. “It’s just adapting. It’s just knowing that once they find the water, they realize the water is a lot warmer. They’ll stay there until that cold streak passes — until the sun comes out and they can re-energize again. They can recharge with the rays of the sun.”

That’s actually helpful information for the growing numbers of python hunters who capture and kill the unwelcome predators throughout South Florida.

“A lot of these snakes are found around the water areas, which is why the python hunters catch a lot of them on these levees,” Magill said. “The levees are always right alongside the canals or the bodies of water. The snakes will eventually come out of the water onto the levees, where they expose themselves to the sun to recharge.”

In general, the larger the snake, the more cold it can withstand over longer periods, Magill said.

Both pythons and iguanas will probably fare better this year than in previous South Florida winters as they pass on their newly honed survival skills from one generation to the next.

“As each year goes by, these animals adapt, and they’ll pass on that gene. I suspect you’ll start seeing iguanas going further and further north as each year passes,” Magill said. “It’s a real problem in southern Florida right now, but I suspect it will become a major problem throughout the state within the next five years.”

This week’s cold weather in Florida won’t do much to reduce the numbers of pythons or iguanas in a meaningful way.

“This cold snap, though it’s strong, it’s not long enough to do lasting damage,” Magill said. “What we need here in South Florida is three to four consecutive days of this kind of temperature.”