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The Journal Gazette

  • Shallotte River Swamp Park  Just before water freezes over, alligators stick their snouts out of the water and go into a hibernation-like brumate state.

Thursday, January 11, 2018 1:00 am

Reptiles slow things down to survive cold

Cleve R. Wootson Jr. | Washington Post

There's a certain Homo sapien arrogance that comes around every time we get a Snowmageddon or a bomb cyclone.

We assume that while we're shivering through single-digit temperatures, most of the rest of kingdom Animalia is similarly struggling.

Consider, for example, the frozen alligators at Swamp Park, in southeastern North Carolina, about the northern extreme for American alligators.

The park, which features an alligator preserve, has been open for two years, but this is the first time the water which the alligators call home has frozen over.

They were unfazed.

When alligators get cold, they brumate, a period of dormancy similar to hibernation. They slow down their metabolism and their breathing and go into a semi-vegetative state. Right before the surface freezes, they stick their snouts out of the water so they can continue breathing.

George Howard, the park's general manager, was one of the first to notice how the 10 alligators were handling the icy water.

At first, he thought the water had too many cypress knees – woody projections from tree roots that are a common sight in swamps.

Then he saw teeth.

He did a Google search, then whipped out his camera and took pictures and videos that he hopes explain what is going on in the park.

“They have been around for millions of years,” he said of the alligator species. “They are one of the only species in existence that is virtually unchanged. And they continue to be good at just surviving. This is just another example of how tough they are.”

Brumating animals don't move much, and their body processes are slowed so much that they don't even digest food. And the park's gators will stay there, seemingly frozen in the ice, until it gets warm.

On Monday, Howard went out on the ice with a local TV crew to show that the alligators were still alive.

He even pulled one up to prove it.

Alligators aren't the only reptiles that sink into a lower metabolic state when it gets cold. Turtles also reduce their activity level and get a little weird when the temperature drops. They get air via cloacal respiration, moving their body across water, filtering oxygen to the most vascular part of their body – their butts.

And in Florida, where temperatures took a rare dip into the 40s last week, iguanas also slowed their bodily functions. But because many are tree dwellers, some just fell to the ground.

It was a repeat of a cold snap in 2010, when the iguana situation caught people similarly unawares.

“Neighborhoods resounded with the thud of iguanas dropping from trees onto patios and pool decks, reptilian Popsicles that suggested the species may not be able to retain its claw-hold on South Florida,” the Sun-Sentinel's David Fleshler wrote.

But the story had a happy ending, Fleshler reported. The iguanas “have rebounded, repopulating South Florida neighborhoods and resuming their consumption of expensive landscaping.”