As the holiday season approaches in South Florida, residents may notice more than the scent of festive meals and the sight of family gatherings. There’s also the unexpected “thump” of green iguanas falling from trees, a phenomenon that occurs when temperatures drop.
But how cold does it need to get before this happens, and what should you do if you encounter a frozen iguana?
When Do Iguanas Start to Freeze?
Iguanas, being cold-blooded creatures, don’t immediately freeze when temperatures fall. Instead, their metabolism slows down, causing them to become lethargic, explains Iguana Control, a company specializing in the removal of the invasive species. According to the Florida Fish and Wildlife Conservation Commission, iguanas begin to slow down when the temperature drops below 50 degrees Fahrenheit.
When temperatures dip into the 40s and 30s, iguanas can experience a “cold stun,” which may cause them to fall from trees. If temperatures continue to plummet, the reptiles can freeze and even die.
The Iguana Falling Phenomenon: Less Common in the Future?
However, experts predict that this phenomenon could become less frequent in the future. Research suggests that iguanas are adapting to warmer temperatures. A study conducted in 2020 by James Stroud, a postdoctoral research associate at Washington University in St. Louis, found that many of South Florida’s common lizard species, including iguanas, are now able to withstand slightly lower temperatures than they could just a few years ago—around 2 degrees Fahrenheit lower. Stroud’s study, published in Biology Letters, found that the critical temperature for most lizards is about 44 degrees Fahrenheit, at which point they freeze up.
Will Iguanas Fall from Trees This Week?
South Florida is expecting a cold front, with temperatures dropping over the next few days. The coldest morning is expected to be Wednesday, when Miami could see lows in the mid-50s. While this may not be cold enough to stun iguanas, suburban areas could experience temperatures in the 40s, particularly in the early hours. If that happens, it’s possible that iguanas may once again rain down from trees.
What to Do with a Frozen Iguana?
Although the frozen iguanas may appear lifeless, experts advise leaving them undisturbed. Once the weather warms up, the iguanas will revive and begin moving again. It’s important not to bring them into your home, as this could disrupt their natural recovery process.
As temperatures shift and iguanas continue to adapt, South Floridians may have fewer iguana-related surprises in the future, but for now, a cold front could still bring the spectacle of “frozen” lizards.
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