Cool critters: Swimming snakes are in waters near you

As you can see from the photograph featured in today’s column, snakes can swim. The picture, taken by a marine deputy with the Boise County Sheriff’s Office earlier this month, shows a large gopher snake moving through a creek as easily as an eel.

Plenty of gopher snakes live here in the Inland Northwest. And chances are, some of them are swimming in a lake, river or creek as you read this. Good news, though – they’re not venomous.

Gopher snakes, also known as bull snakes, reach lengths of 6 feet in the Pacific Northwest, and the species is “common and widespread” in Eastern Washington, according to the Washington Department of Fish and Wildlife.

Yes, gopher snakes are big – just like the one in the photograph – and it can be startling to see one slithering along as you paddle a canoe or take a refreshing dip on a hot day. Rest assured, whether in the water or out, “they’re harmless,” said Charles Peterson, professor emeritus of herpetology at Idaho State University.

“Like humans, they live on land but will enter bodies of water and get around quite well,” he said.

But unlike humans, gopher snakes don’t go in the water as a form of exercise, to splash around with buddies or compete in open-water swim competitions. Which begs the question: Why do they?

It could be to cool off in hot weather, to escape an on-land predator such as a fox, racoon or coyote, or simply to move from one part of the snake’s habitat to another to find food, Peterson said.

“The snake’s den could be in one location and a more abundant food source in another,” he added.

As it turns out, gopher snakes don’t have the corner on swimming. With nearly 4,000 snake species worldwide, it’s impossible to know how many of them swim.

Some are rare or endangered. And in some parts of the world, certain species are rarely seen leaving the treetops and caves they inhabit. In an analysis of 525 snake species published in the November journal Zoology, researchers found that “all snakes for which information is available appear to be able to swim.”

Both the gopher snake and the smaller-sized garter snake commonly move through our region’s waters with utmost ease, said Peterson, adding that the garter snake is the more aquatic species because it hunts fish and amphibians along the way.

“Most snakes are capable of swimming, with some being better adapted to aquatic settings than others,” he said.

Among the most adept swimmers are sea snakes, which spend their entire lives in the ocean, and water snakes that live in and around fresh-water habitats in the eastern half of the United States. Happily, our country’s only venomous water snake is the cottonmouth (also known as the water moccasin), which lives in the southeastern states.

Snakes have no fins, no webbed feet and no limbs. How, then, do they swim?

Like those tubular pieces of foam called water noodles, snakes are buoyant, so they don’t sink. They also propel through water similarly to the way they move on land – by moving their bodies in a side-by-side S-shaped motion, Peterson said, a movement known as lateral undulation.

Let’s get back to that gopher snake in the photograph. Look closely. Notice its forked tongue?

“The snake is probably trying to figure out if there’s a nearby threat by flicking its two-tined tongue as a way to ‘smell’ its surroundings in stereo,” Peterson said.

“It’s what snakes do. They draw in scent particles to gather information about their environment.”

Judging by the Facebook post made by the Boise County Sheriff’s Office, the marine deputy who snapped the picture wasn’t the least bit concerned. Should you encounter a tongue-flicking gopher snake swimming in the water, here’s what the agency advises you to do:

“Just give ’em some space, toss ’em a howdy, and let these slippery fellas do their backstroke on outta your way.”