Rain-harvesting rattlesnakes give new meaning to 'thirst trap'

You are in the desert and are dying of thirst. Suddenly, storm clouds appear overhead and small liquids begin to spew from the sky. How can we quickly make the most of potentially life-saving precipitation?

One more thing, you don't have any hands.

Prairie rattlesnakes have evolved a simple solution to this problem. They just coil up and turn into rain-collecting pancakes.

“This is a behavior we see in several different species of snakes,” says Scott Bobak, a herpetologist and ecologist at Dickinson College in Pennsylvania. But “most of that information is very anecdotal.”

After all, rattlesnakes hate being spotted. And in an arid environment, precipitation is rare. If Dr. Bobak and his colleagues wanted to study the phenomenon of rain collection, they realized that they needed to make it rain.

Dr. Bobak and his team used garden sprinklers and video cameras to record nearly 100 snakes responding to simulated rainfall at a famous rattlesnake hibernation site outside Steamboat Springs, Colorado. This allowed us to quantify the behavior and divide it into stages.

Not only did they watch the snake swallow its own flattened body and the ground, but they also watched it lean down and swallow the snake next to it. They also found that snakes in large groups were more likely to swallow other snakes than snakes in small groups.

“Some of the aggregations are literally huge,” said Dr. Bobak, author of a study describing their behavior in the journal Current Zoology published in late 2024. of snakes. ”

All of this suggests that warmth and protection may not be the only benefits for rattlesnakes that nest in groups.

Interestingly, the scientists also observed how some rattlesnakes cantilever their coiled bodies onto ledges, creating horizontal rain-collecting platforms on uneven ground. . Snakes would also tilt their entire coiled bodies forward to coax water toward their mouths, similar to how we use a bowl to slurp up the last sips of tomato soup.

Most curiously, about a dozen of the snakes appeared to be drinking water that had fallen on their heads and was delivered to their mouths by some unknown mechanism. “We don't know what's going on there,” Dr. Bobak says.

None of this would be possible without the strange and minute arrangement of a rattlesnake's scales. The scales are hydrophobic enough to bead water droplets, but hydrophilic enough to prevent them from flying off the reptile.

“There are similar examples in plants,” said Konrad Likaczewski, a mechanical engineer at Arizona State University who was not involved in the study. “When it rains, go look at the rose petals. You'll see big water droplets attached to them.”

In a 2019 study, Dr. Likachevsky showed that desert rattlesnakes have the ability to catch this rain, but that gold snakes, which live in the same area but have smoother scales, do not.

Dr. Likaczewski called the new study “very impressive,” but said he was unsure whether snakes had channels in their heads that channeled water, similar to what has been shown in the Texas horned lizard. There wasn't. He's in no hurry to find out either.

“I mean, a dead rattlesnake can still bite you, right?” he laughed.

Gordon Schuette, an evolutionary ecologist at Georgia State University and co-author of the study with Dr. Likachevsky, said he has witnessed rain-harvesting behavior many times in the field. But the new study's substantial sample size and detail are what make it “a standout.”

Ultimately, Dr. Bobak hopes that the sight of rattlesnakes peacefully drinking water from each other will show more people that rattlesnakes are social beings, with behaviors that are more intimate and complex than we traditionally believe. I hope that it will be able to remind us that we have a certain kind of character.

“There have been videos of snakes swallowing each other's heads, and it seems like the cutest thing in the world,” Dr. Bobak said. “They almost look like they're kissing.”