It’s been a cold winter in North Carolina. Local alligators are feeling the chill as January nights slip below the freezing point, turning their swampy homes into skating rinks. What’s an iced-out alligator to do? As employees at the Shallotte River Swamp Park in Ocean Isle Beach documented in a weird video on Tuesday, the gators did the obvious: literally chill.
The video, posted to Facebook by the Swamp Park, shows the park’s famous American Alligators with their frowning snouts sticking up out of the solid pond ice. “Eighteen American alligators are thinking ahead as they poke their noses up through the ice here in January 2019,” says George Howard, the park’s manager, in the video.
Thinking ahead? you may ask. Why, yes: These alligators may look frozen solid but are still very much alive, riding out the cold snap in a state called brumation.
Brumation is a lot like hibernation, the dormant state that mammals go into to survive cold temperatures. During brumation, a reptile’s physiological processes slow down (like breathing, heart rate, and body temperature regulation) in order to save energy, though it doesn’t fall into a deep slumber like a hibernating bear. Instead, it stays still in warm areas like mud holes, as long as temperatures allow. It won’t eat during brumation, but it will drink water to stay alive and occasionally bask in the sun to raise its body temperature, according to experts at the South Carolina Aquarium.
The frozen-pond posture is mean to keep a reptile’s body temperature high and energy expenditure low while getting the air it needs to survive. In 1990, an article in the ichthyology and herpetology journal Copeia explained that sticking a snout out of ice is actually a good way to keep the rest of an alligator’s body warm.
Adult alligators bask on warmer winter days and, in response to freezing weather exhibit a submerged breathing posture in which the tip of their snout is kept out of water while the rest of the body is extended into deeper/warmer water. Hence, adult alligators survive freezing conditions by maintaining air holes in the ice of frozen ponds, rather than by staying submerged under the ice.
It isn’t just alligators that do this. In 2018, after a bomb cyclone blanketed South Florida with snow, Inverse reported that local residents were startled by frozen iguanas falling out of trees. As with North Carolina’s gators, it was not a big deal: The iguanas found it too cold to bother trying to live normally, so they entered brumation until things heated up.
Healthy reptiles that have stored up enough energy before entering brumation should be able to come out unscathed. Florida’s iguanas were fine: “Even if they look dead as a doornail — they’re gray and stiff — as soon as it starts to heat up and they get hit by the sun rays, it’s this rejuvenation,” said Ron Magill, communications director for Zoo Miami, in an interview with The New York Times about the iguanas.
Likewise, the alligators at the Swamp Park have done this before. They were filmed in similar postures in January 2018, and when they thawed out they were “irritable,” according to the Charlotte Observer.
“You hear him hissing?,” said Howard about the unfrozen alligators. “Wow. He’s not real happy with me.”