Iguanas dropping from trees, manatees huddling around waters warmed by power plants and marine turtles being whisked away to shelters -- Florida's unusual cold snap is a deadly one for tropical wildlife. When temperatures drop below about 60 F (15 C), they become less able to move around. Below about 40 F (5 C), they become completely immobile due to a lack of blood flow.

Iguanas dropping from trees, manatees huddling around waters warmed by power plants and marine turtles being whisked away to shelters -- Florida's unusual cold snap is a deadly one for tropical wildlife.

The cold front sweeping in from the Arctic, with temperatures below freezing in parts of the southeastern state, is killing many animals accustomed to a temperate climate that sends droves of tourists swarming to enjoy yearlong warmth in the "Sunshine State."

The cold-blooded iguanas' comfort level begins at 73 degrees Fahrenheit (23 Celsius) and they positively thrive at 95 F (35 C).

When temperatures drop below about 60 F (15 C), they become less able to move around. Below about 40 F (5 C), they become completely immobile due to a lack of blood flow. Unable to hold on, the mohawked lizards, which shelter in tree branches and crevices, drop to the ground.

Iguanas and other tropical wildlife are bearing the brunt of the severe Arctic weather in Florida, where Miami's subtropical beaches have been left all but deserted this week with temperatures plummeting to around 32 F (zero degrees Celsius).

"Cold weather impacts iguanas severely and many are killed," said Gabriella Ferraro, spokeswoman for the Florida Fish and Wildlife Conservation Commission (FWC).

"That is not a bad thing. It's a good thing, because iguanas are an exotic animal, they don't belong to Florida. This seasonal kill helps us to manage the population."

Travelers from Mexico, Central and South America originally introduced the creatures to Florida in the 1960s.

Although suffering from the cold, python snakes, which abound in particularly large numbers in Florida's Everglades swamp reserve, can survive in cooler temperatures.

"The good thing is that the cold weather brings the pythons out of the vegetation. They need warmer bodies and they come out to get some sun and so it is easier for hunters to find them," Ferraro explained to AFP.

Manatees and sea turtles are the most vulnerable during the cold weather, she added, noting that some of the animals had died in central Florida.

Known as sea cows for their bulky frame -- adults are an average of three meters (10 feet) long and weigh between 800 and 1,200 pounds (360 and 540 kilograms) -- manatees abound in Florida's warm waters close to river mouths and can die from prolonged exposure to low temperatures.

When water temperatures drop, manatees gather in warm-water habitats, such as discharge canals at power plants, canal systems or springs to avoid a deadly "cold stress syndrome."

With thermometers dropping to record lows, large groups of manatees huddled in recent days seeking the warmth of power plants in Riviera Beach, north of Miami, and Apollo Beach, near Tampa off the Gulf of Mexico.

The FWC says it has rescued about 250 sea turtles so far and placed them in special shelters where they can rest while waiting for the sea to warm.

The seemingly lifeless iguanas can be revived, however. Passersby can usually bring them back to life by picking up the lizards and setting them in the sun. After a brief warm-up, most will scamper off into the bushes.

Florida's exotic creatures may have to brace for worse, with forecasters saying a new polar front could sweep in over the weekend in the state, where some parts have already seen temperatures 20 degrees below normal.

Explore further Record number of manatees counted in Florida

(c) 2010 AFP