While trying to retrieve the Ark of the Covenant, Raiders of the Lost Ark hero and noted ophidiophobe Indiana Jones finds himself in a hibernaculum full of hundreds of writhing snakes. I don’t have the same fear of snakes that Indy does, but I’m coming to find snake ID absolutely terrifying.
A few weeks ago, we posted a photo of a snake on our website as part of our biweekly guessing game, What in the Woods is That?, or as it’s known around the office, WITWIT. I wasn’t 100 percent sure what the snake was, but I figured it was likely a ratsnake. No worries, I thought, I’ll just ask around and see what people-in-the-know say.
But as the date to post the answer approached, I found myself lost in my own writhing pit of snake species: eastern ratsnake, black racer, northern water snake, indigo snake – all these different identifications for the snake in the photo, most from trusted sources.
One person suggested northern water snake, what with the dark coloring and triangular head. Plus, the snake appeared to be lounging on a beaver lodge, which was confirmed by our board president Julia Emlen, the person who took the photo. Emlen added in an email: “The folks at Mass Audubon’s Ipswich Center identified it as a northern water snake. The secret in identification seemed to be the rectangular head that was almost separate from the body.”
OK, I thought, so it’s a water snake. I double-checked with naturalist Ginny Barlow, Northern Woodlands’ co-founder.
“I’m voting against water snake,” Barlow said. She noted one field guide that said the coloration of the northern water snake “is highly variable, although they are generally dark in color with a banding pattern forward, and with lateral and dorsal blotches over the rest of the length.”
“We would see lateral blotches if they were there,” Barlow said. “Also, the photo shows a head that’s very different from the body.”
Another trusted source, a biologist, had this to say: “It’s an eastern ratsnake (Pantherophis alleghaniensis), formerly called a black rat snake.”
When I asked if it could possibly be a northern water snake, he emailed me back: “Nope. Northern water snakes always retain a distinct pattern on the dorsal side. Rat snakes are patterned as young, but turn black later. Their bellies always have a checkerboard-type pattern.”
Good enough for me, or so I thought. I posted the answer as eastern ratsnake, and in came the emails decrying otherwise.
“Your snake is a northern water snake (Nerodia sipedon),” wrote one herpetologist. “The older adults are often mistaken for other ‘black snakes’ because as they age they become darker and darker. In addition, the remnants of their juvenile pattern show up better when they are wet. When the snake is dry they look darker. You can see some of the red coloration on the edge of the belly and even on the side. Your snake is heavily keeled, has a flat-sided head with vertical bars on the lower lips, and it appears it might even be basking on a beaver lodge that are favorite basking locations for northern water snakes. Eastern ratsnakes have weakly keeled scales and show white flecking between the scales on their bodies.”
Sigh.
Another reader wrote in: “I'm not sure it is not a black racer. I can't rule it out.” After studying range maps of the ratsnake and blowing up the photo as much as he could to get a good look at the snake’s scales (keeled or not?), he said that he agreed with our ratsnake identification, “tentatively,” but that the “range is wrong and the habitat seems to be as well.”
Double-sigh.
While I absolutely love hearing from readers and thoroughly enjoy the fun that ensues from trying to identify a wild plant or animal, the editor in me feels embarrassed at my poor decision to post a photo for an identification quiz without knowing the subject’s true identity. I guess the main lesson here is that a photo cannot always provide proof-positive, and one needs to remember that even experts can disagree on something as seemingly simple as a snake in a picture.
After hearing from all of you, and weighing the evidence, and squinting at dozens of pictures, we’re coming full circle and changing our answer. The snake in the picture is (almost surely) a northern water snake. When I shared readers’ reactions with my initial source, he had this to say:
“Your readers are astute -- more so than I. On second look, it does appear to be a northern water snake, which rarely lack patterns on their back (only the largest, older individuals lose the pattern). I completely missed the orange edging peeking in along the sides. My humblest apologies for the miss-ID, especially after you specifically double-checked about water snake. Oh well, it's always good to get multiple opinions, particularly for photo IDs. I'll go have a snack of humble pie now.”
Save me a piece of that pie, please.
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