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Northern Brown Snake
Northern Brown Snake: Welcome
Did you turn up a small, plain snake in the garden? Did volunteers run screaming at the cleanup event when they found a snake (SNAKE!!!) under a piece of trash?
Odds are, it’s a brown snake, the most urban of Philadelphia’s snakes. They live quiet lives in parks, gardens, vacant lots, and any other green spaces with a little cover to hide under.
Brown snakes (Storeria dekayi) rarely grow longer than a foot long.
Their name fits. They have brown or tan background color with parallel rows of light spots down the back and a lighter stripe down the middle. They have a little bit of a checkered pattern down the sides, especially noticeable when defensive brown snakes puff themselves up to look impressive.
They are often confused with garter snakes (Thamnophis sirtalis), and lots of times, when someone says they found a “baby garter snake,” they’re talking about a brown snake. Garter snakes usually have a stronger pattern on a greener background, including a stripe on each side just above the belly scales, which brown snakes lack. Garter snakes also have proportionately larger heads with big eyes.
Brown snakes eat snails, slugs, worms, and other soft-bodied invertebrates.
Brown snakes spend most of their time cover, hiding where they can escape the notice of predators (which is a big category - other larger snakes, birds, and mammals like raccoons and foxes).
They mate in the spring, and give birth to live young in late summer. A fat brown snake you find in June is probably gravid (like being pregnant, for snakes), and later on, you’ll find the tiny babies under the same kinds of cover objects as you do the adults.
Brown snakes will puff themselves up and strike in defense, but their mouths are too small to bite humans. They will poop and musk if picked up.
Where Brown Snakes Live
Brown snakes live in a wide range of habitats, including wetlands, old fields, and urban gardens and vacant lots.
Observing Brown Snakes
Though they sometimes bask in sunny weather, brown snakes survive by staying out of sight of people as well as the endless list of animals that eat them. You can find them by looking under surface objects. That can mean rocks or flower pots in your garden or old boards, clothes, or other trash in a vacant lot.
Always replace the brown snake’s cover object (its roof) BEFORE you release it to avoid smooshing it by accident. If you’re not planning to pick it up, brush it aside. It will find its way back underneath.
Be sure to snap a picture with your phone or camera and add the observation to iNaturalist. Please also join the Pennsylvania Amphibian and Reptile Survey (PARS) project in iNaturalist and add your observations to it. PARS is a state-sponsored citizen science project to learn more about PA’s amphibians and reptiles. Your observation will support scientific research and conservation efforts.
Remember that PA requires you to have a fishing license to catch reptiles and amphibians. It’s a good deal, and the funds from licenses support conservation and research efforts.
Living with Brown Snakes
Brown snakes do pretty well in the city, but you can help them by cutting pesticide use in your own garden. Most importantly, keep unattended cats inside, and don’t feed stray cats. Cats kill tons of brown snakes and other small animals.
Check out brown snake observations on iNaturalist
Northern Brown Snake: Text
It pays to stay out of sight if you're an urban snake. Learn how to find our most urban of snakes, the brown snake. Thanks to our partners at Grid Magazine for producing the video and to the William Penn Foundation for their support.
Northern Brown Snake: Video
Northern Brown Snake: Image
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