As a kid back in the 1990s I was absolutely positive I had both Common Gartersnakes and Eastern Ribbonsnakes slithering around in the fields behind my house, but today I chalk that up to some shotty use of a field guide on my part. Gartersnakes are widespread in Vermont and the only species of snake many people in the area ever encounter, myself included at that point in time. Most people recognize them as the gray or black snake with a yellow stripe down their backs that hang out around gardens, patios, and rock walls, and folk more or less leave it at that. But to some people’s surprise, we actually have two species of snake in the state that fit that description, and distinguishing a Common Gartersnakes from Eastern Ribbonsnakes requires a much closer look and fine attention to detail.

Eastern Ribbonsnake with a clean black background, distinct yellow stripes, and slender form.

First, I need to establish one thing. Eastern Ribbonsnakes are incredibly rare in Vermont. Though they may be common in the Southeastern United States where many of our followers live, they are very difficult to find through most of Northern New England. In Vermont, we only know of current populations in Western Rutland County and near the Connecticut River in Windham County. Historically, they also occurred near Lake Champlain in parts of Chittenden and Grand Isle Counties, but efforts to locate Ribbonsnakes there in the past thirty years have been unsuccessful. Yet, due to their similar appearance to garters, populations of ribbons may be hiding in plain sight. 

Side by side comparison of a Common Gartersnake (left) and Eastern Ribbonsnake (right)

So, how can you tell a Common Gartersnake and Eastern Ribbonsnake apart? First, at a glance, the Ribbonsnakes are a much more slender species and their pattern is very clean – the yellow stripe on the back is very distinct and contrasted by a uniformly dark dorsal background. The head of a Ribbonsnake is dark brown, almost reddish, and their lower jaw jaw and lips are a distinct white color. Both species also have yellow stripes along their sides, but if you count scale rows starting at the belly, the stripes on Ribbonsnakes are one row higher (on rows three and four). Below those lateral stripes, Ribbonsnakes also have a distinct mahogany band. Plus their tail is longer – about a quarter the length of the body or more. 

This up close photo of a Ribbonsnake's head clearly shows the reddish brown head and white upper lip that helps distinguish it from a Gartersnake. The white patch in front of the eye also helps.

Gartersnakes look dirty by comparison and have white marks between their scales that create an almost checkerboard pattern along the back of the snake, especially when the snakes inflate themselves to deter predators and after they have eaten large meals, causing their skin to stretch. Their head is more of an olive green color, and their lips and neck are yellow. The stripes on their sides are lower (scale rows 2 and 3) and do not typically have any mahogany beneath. Their tails are shorter, usually around a fifth the length of the body. That is how a Common Gartersnake usually looks anyway, but to keep us on our toes, the species is highly variable and doesn’t always resemble pictures or illustrations in field guides. 

Common Gartersnakes, by comparison, look much dirtier compared to ribbons and often have a checkerboard pattern on their skin, especially when they puff up or have bellies full food.

Apart from physical appearances, the two species have different habitat preferences. Ubiquitous across the region, garters inhabit just about every field, forest, wetland, and open space in the state, including in urban settings. Ribbons, however, should be thought of more as a wetland specialist and thrive only in wet open areas with surrounding warm meadow habitat. In Vermont, we really only have what Ribbonsnakes need in parts of the Champlain and Southern Connecticut River valleys. 

This poster points out a handful of field marks that help distinguish Gatersnakes from Ribbonsnakes.

Often, when folk send in reports of Ribbonsnakes up here, close examination reveals that the snake in question is actually a garter, so photo documentation is borderline essential for the observation to be verified. As a highly variable species, sometimes garters can very closely mimic the ribbon’s appearance, but it is highly likely a small handful of ribbon populations may be hiding in plain sight. Every now and then, ribbons are documented in new parts of Western Rutland County and presumably that will happen again, but verifying a new location getting new documentation from within the Connecticut River Valley or anywhere in the central or northern Champlain Valley would be very exciting.

Thankfully, a partner of ours, the Vermont Reptile and Amphibian Atlas, keeps track of such information and uses the data to help inform management decisions and conservation priorities for rare reptiles and amphibians in the area. If you believe you have found a Ribbonsnake in Vermont, the atlas would love to hear about it. And if you live somewhere else, perhaps the information will be equally valuable there; many states have herp atlases that would love to hear about your observations. Absent that, there are also citizen science apps such as iNaturalist and HerpMapper. You can also do a little research and look for other species local biologists would be excited to learn more about. The point here is that if you keep your eyes open and learn how to identify rare and unusual species to watch out for, you may be able to contribute very useful information to local conservation efforts. Even if you don’t find anything rare or unusual, reports of common species are also tremendously useful. And please, if at all possible, take pictures that show off those field marks! Reports can still be useful without photos, but for rare species that look similar to common ones, photos make the reports much more valuable. 

And if any doubt remains, comic by a friend to The Orianne Society, Rosemary Mosco, may help shed some light on the matter.
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