Snake on the Water

Philly’s creekside rockstar gets its moment in the sun.

The best thing you can do if a thick brown snake ever hisses at you in the Wissahickon, is remind yourself there are no venomous snakes in the Philadelphia area. None. Zero. Zilch. That grouchy serpent holding its ground is the Northern Water Snake, harmless to humans, but a heavyweight in our local ecosystem: part predator, part prey, and all attitude.

Go ahead and freak out, though – this species can be quite a fearsome sight! Up to four feet in length and as thick as your wrist, with a head that flattens into a viper-like wedge when threatened. Their bodies are heavier than most other nonvenomous snakes, and their dark scales, patterned in blotchy browns and reddish bands, could easily be taken for a rattler or a cottonmouth at a passing glance.

While water snakes strongly prefer to avoid humans altogether, if cornered they will put on quite a show, hissing and lunging and even “musking” attackers with a milky, foul-smelling oil from their tail glands. They don’t have fangs but they will strike when provoked, and though the resulting wound will be minor it’ll bleed more than you’d expect thanks to an anti-coagulant in their saliva. Talk about a nope rope!

Whether we like it or not, northern water snakes are the most common aquatic snakes in our region, found along the banks of the Wissahickon, Cobbs Creek, Bartram’s Garden, the Manayunk Canal, and even the Schuylkill River. They’re so expertly camouflaged and avoidant, though, unless you’re really paying attention, you might never know they’re here.

Northern Water Snakes (Nerodia sipedon sipedon) are natural swimmers and cold-blooded baskers. They hunt fish, frogs, and tadpoles in the shallows and rocky outcrops, and you might also spot them gliding across the surface of the water. They’ll often weave themselves into low-hanging branches along waterways, or coil up like a bump on a log. On nice days, you might catch them sunbathing along with painted turtles, their shelled ecological counterparts.

A typical water snake diet includes fish, frogs, tadpoles, worms, young turtles, large insects, and even small birds and mammals. Both predator and prey, they help regulate populations of fish and amphibians, and in turn become meals for birds, turtles, raccoons, and larger snakes. They’re also a sign of decent water quality — if the creek is clean enough for a snake to hunt in, that’s good news for the whole food web.

And they’re one of the few snakes in our region that give live birth —no eggs! Babies are fully formed and independent at birth, sometimes as many as thirty in a litter. If you’re lucky (or unlucky, depending on your comfort level), you might see a whole knot of them basking together in late summer. ☀️😎

By mid-to-late October as the sun loses strength and creeks run cold, water snakes vanish from sight — retreating into cracks, burrows, and root masses to wait out the freeze. Come spring, they’ll slither back into the light, ready to cruise the banks once again.

If you see a Northern Water Snake, consider yourself lucky — and give it space. They don’t want anything to do with you, and they couldn’t harm you if they wanted to. They’re just out here, like the turtles and the herons and the minnows, making the most of a hot Philly summer.

🐍 10 FUN FACTS

• Northern water snakes can hunt underwater, striking and capturing prey even while fully submerged.
• While not actively social creatures, water snakes will pile up to bask. A heap of snakes doesn’t mean a nest — just a great spot to warm up (in the spring, though, it could be a mating ball 😳) .
• A newborn snake is called a snakelet or “neonate.” A bunch of snakes all intertwined is called a “knot” (as in, I’d rather “not” get close to this).
• The largest northern water snake ever recorded was a female from the mid-Atlantic region who stretched almost 5 feet, a whopping 45% bigger average.
• Like most snakes, water snakes shed their skin in one single piece, including the clear scale over each eye. Youngsters will shed often as they grow while adults can shed to heal damaged skin or shake off parasites like ticks and mites.
• Although a water snake’s lifespan is about a decade, few make it full term. The oldest one in captivity lived 9 years 7 months.
• It’s a myth that water snakes will chase you. It often looks like they’re running at you when really they’re just trying to flee (and you’re standing in the way).
• The original “snake oil” was water snake fat, a Chinese remedy rich in omega-3s that really worked. When Wild West salesmen tried to make their own from rattlesnakes, the results (and their reputations) fell flat.
• The largest of the 88 constellations is Hydra – a female water snake that slithers across nearly a quarter of the night sky from February through May.
• In many Native American cultures, the water snake is a symbol of healing and rejuvenation. A sighting may signal that change or transformation is on the way.

⚠️🍼 BABY SNAKES ON BOARD  August is prime time for snake birthdays! 🥳

While Northern Water Snakes give birth to live young, females don’t build nests or care for their offspring. Sometime in late August to early September, they’ll deliver litters of up to 30 tiny snakes, each one fully formed and ready to swim, hunt, and hiss their little hearts out.

The newborns are 8 to 12 inches long, boldly patterned with reddish bands and blotchy bellies that fade as they grow. You might spot one warming up on a sunny log or darting through shallow water — or even several piled together near the edge of a creek.

Don’t panic! Baby water snakes aren’t aggressive and pose no danger to people or pets. Consider it a serendipitous sighting, and proof that even in the city, nature still has surprises.

❓🤔 Water Snake or Moccasin? One’s common in Philly. The other doesn’t live here.

Next time someone’s ready to go medieval on innocent wildlife, here’s how to talk them down:

• Water snakes have blotchy, banded patterns that often look stripey, while cottonmouths display more defined, hourglass-shaped bands.
• A water snake’s head may flatten when threatened, but it’s still more oval and less distinct from the body than a cottonmouth’s wide, triangular head.
• Water snakes have round pupils, while cottonmouths have slit-like pupils.
• While both can hiss and stand their ground, only the cottonmouth is venomous — and again, not local.

🛑Nearly 100% of venomous snakebites in the U.S. happen when someone tries to handle or kill a snake. The safest move — for everyone — is to just leave it be.

Thoughts? Comments? Please leave them below. If you enjoyed this Local wildlife feature, please check out last month’s spotlight on the Water Snake’s slow-footed cousin, the Eastern Painted Turtle.