‘Tis the season for ‘falling iguanas’ in South Florida

South Florida Battles Invasive Iguana Population
MIAMI, FL - MARCH 13: Iguanas are seen as the Florida Fish and Wildlife Conservation Commission continues its efforts to try and control the invasive species on March 13, 2018 in Miami, Florida. The commission has teams of people that are trying to eliminate the reptiles by killing them, which would prevent them from eating native plants and wildlife as well as disturbing the natural Florida habitat that they are living in. (Photo by Joe Raedle/Getty Images)

The National Weather Service in Miami is calling for “falling iguanas” in its holiday forecast.

Temperatures in South Florida are expected to drop into the 30- to 40-degree range on Christmas Day and into the weekend, creating conditions that may cause iguanas to suddenly drop out of trees, the NWS said on Twitter.

Iguanas can’t handle cold weather because they are cold blooded, so when the temperature drops below about 45 degrees their bodies go dormant. They appear to be dead, but they are not. They remain breathing with critical body functions still operating.

This phenomenon, mixed with the species’ tendency to sleep in trees, can create quite the surprise for someone in a car or walking under a tree, and since some iguanas are large — adult males can reach 5 feet in length, and weigh up to 20 pounds — this can be dangerous to passersby.

The danger for the iguana comes when temperatures remain in the 40s for periods over eight hours. The invasive species is then at risk of death, especially the smaller ones.

“The temperature threshold for when iguanas begin to go into a dormant state depends greatly on the size of the iguana,” Ron Magill, communications director for Zoo Miami told CNN when the temperatures dropped in January. “Generally speaking, the larger the iguana, the more cold it can tolerate for longer periods.”

He also commented that many iguanas in South Florida have adapted to digging deep burrows, so they are insulated from the cold. Iguanas also tend to live close to large bodies of water, which can be warmer than the air temperatures, so it can help them survive short cold snaps.