The very rare Eastern Ribbonsnake looks very similar to the much more widespread Common Gartersnake. They both have three yellow, length-wise stripes on a dark background. In Vermont, all snakes with yellow stripes should be assumed to be Common Gartersnakes unless the head markings suggest otherwise. Eastern Ribbonsnakes have a bright white upper lip. The tops of their heads are reddish-brown , and they have a thin black line behind their eyes. In addition, there is a vertical white bar in front of the eye on Easter Ribbonsnake. The shiny white upper lip of an Eastern Ribbonsnake can be seen from quite a distance. Usually the sides will appear solid black. The stripes are well-defined and higher (scale rows 3 & 4) on the sides than in the Common Gartersnake (scale rows 2 and 3). Also look for the mahogany stripe along the lower sides and edges of the belly. The ribbonsnake is more slender than the gartersnake. The scales of both species are keeled.
The tail (find the vent) is between ¼ and ⅓ the total length of the body and very tapered. Eastern Ribbonsnakes may reach 2-3 feet long (the longest documented in Vermont is 35 inches).
- Eastern Ribbonsnake head markings: bright white upper lip, reddish-brown on top of head, straight black line behind eye, vertical white bar in front of eye (a very rare snake in Vermont).
- Common Gartersnake head markings: yellowish upper lip, olive green on top of head, no black line behind eye, no vertical white bar in front of the eye, yellowish “ear” spots (a very common snake in Vermont).
View or download a poster of the two snakes showing the differences: Wanted: Ribbonsnake sightings poster
The Eastern Ribbonsnake may be found in pastures, open woods, and rocky areas but they are almost always near water.
This species has a state natural heritage rank of S2. The Eastern Ribbonsnake is rare in Vermont and is a species of special concern. It has been designated a Species of Greatest Conservation Need (high priority) in Vermont’s Wildlife Action Plan.
Please report all sightings of this species in Vermont. Take photos if possible. Even historic sighting information is useful. Before you report an Eastern Ribbonsnake, please review these key differences between Ribbonsnakes and Gartersnakes (PDF).
- Thamnophis sauritus at Animal Diversity website
- Thamnophis sauritus at Canadian Herpetological Society website
- Thamnophis sauritus in the Vermont Agency of Natural Resources’ Wildlife Action Plan: Amphibian & Reptiles (9/25/2015 draft)
- Thamnophis sauritus at the Snakes of Massachusetts website
Species summary written by Ariel K. McK. Burgess.