Common Gartersnake (Thamnophis sirtalis)

Species Information

Recognized Subspecies in VA: Eastern Gartersnake (Thamnophis sirtalis sirtalis)
Size: 18 - 28 inches
Range: Statewide, but rare on the Eastern Shore
Status: Least Concern 

The Eastern Gartersnake is the official state snake of Virginia. This species is common in many habitat types in the state, especially near water. They are usually quite abundant in suburban areas as well, as typical yard conditions suit this species very well. Believe it or not, Gartersnakes are rear-fanged venomous snakes, though their venom is completely harmless to people. Gartersnakes are named for their pattern of checkers that resemble checkered garters. This species mostly feeds on frogs, salamanders, fish, earthworms, and other similar items. This species is one of the few social snakes species found on the planet, and often form clicks with a few other snakes. If a Gartersnake is separated from its "friends", it will often die of loneliness, so please do not relocate this species. 

Finding Gartersnakes is pretty straight forward. They can be found under debris, basking, road cruising, or just at random. Many people find them in their gardens (where frogs come to eat pest insects) or in and around in-ground swimming pools. Streams also provide good water sources for these as well as ponds.

​Gartersnakes are quite variable, especially across the state. There are a few variants that I separate out to help. The first is the "Piedmont Gartersnake". These are typically yellowish with brown, olive, or gray stripes with two clear rows of black checkers in the stripes. These are found across the Piedmont, and  spill over into the coastal plains and mountains. Second is the the "Tidewater Gartersnake". These are usually more beige, with tan, olive, or orangey stripes with smaller, black checkers in the stripes. These are found in the Great Dismal Swamp and east to Virginia Beach, but do not venture too far north. That said, the rare Gartersnakes on the Eastern Shore are almost identical. Then there is the "Mountain or Montane Gartersnake", which is quite variable. These are usually a drab yellow, with  large, dark checkers. These start in the Blue Ridge and run west, but this variation is dominate in NOVA where it seems "Piedmont Garters" have some influence. The "Valley Garter" seems to be found at lower elevations in the mountains. These tend to be pale yellow with fairly clear stripes, similar to a Ribbonsnake. Finally, we have the "Highland Gartersnake". These snakes look unlike any of the other Garters, with a tan to olive base, greenish to mahogany to brick red stripes and faint checkers. All of these variations have blue-green skin under the scales, but it pops in such a way with this variant. This variation can be found in parts of Highland County over 4,000 feet in elevation, and Grayson Highlands area. 

Similar Species: Gartersnakes are often confused for Eastern Ribbonsnakes, which have clean, unpatterned lips (Eastern Garters have bars on the edge of the labials) and a white crescent in front of the eye. The light stripes on the flanks of the Garter run along the edge of the ventral scales, while Ribbons have a gap between this stripe and ventral scales. Dekay's Brownsnakes are also often mistaken for Gartersnakes, but they are smaller, with an under-eye stripe and their top row of checkers often straddle their mid-dorsal stripe. 

Eastern Gartersnake vs. Eastern Ribbonsnake

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​Maps and External Sources

Known and predicted range

***iNaturalist maps show iNat reports of each species. Though maps are quite accurate, some reports could be misidentified, so be cautious of any outlying records.***

VHS Info

iNat Observations