Northern Cottonmouth (Agkistrodon piscivorus)

Species Information

Recognized Subspecies in VA: None
Size: 30 - 48 inches
Range: Southern Coastal Plain
Status: Least Concern

Though other species are often confused for them, the Northern Cottonmouth is only found in the Coastal Plain, south of the James River. Cottonmouths do not like open water, and prefer cypress swamps and marshes, though they can be found along some shady edges of rivers or lakes in the region. They can be found by road cruising roadways through the appropriate habitat, flipping boards near water, or just out basking during the day. 

Though this snake is venomous, they rarely frequent areas that people inhabit. They are extremely curious, but very placid, and non-aggressive. They will swim directly up to one’s boat or feet if allowed, and then they will leave content with you not being edible. Cottonmouths will hold there mouths open, pointed directly towards the threat, when bothered. This said, they rarely strike. I have tapped their mouths with my snake hook several times, and never had one strike. They will hold this position until they can flee, even if it takes several minutes. The name Cottonmouth derives from this behavior, as “cottonmouth” being a term for dry-mouth, and not for their mouth color, though it is quite pale. The only time they usually strike, if when it is the last ditch effort to survive. There is very few Cottonmouth bites in the state, and only one fatality, coming from an intoxicated individual, that played with the snake, including throwing it on people, for hours.

Cottonmouths are stocky snakes, with very large, pointed heads. Their heads are much deeper than that of the Copperhead, and the Cottonmouth has a clear mask through the eye. They are various shades of brown, with dark “pixilated” bands, though on dry snakes near shed it may be difficult to see these bands. That said, the shape of the snake is very unique. 

Similar Species: There are not many similar species, though I have seen people confuse Central Ratsnakes for this species… The truly similar species would be the Eastern Copperhead, which has a smaller head and contrasting, brown bands. The Northern Watersnake is often confused as well, though these have brown bands as well as a smaller, head and a narrower body. The Plain-bellied Watersnake is also similar, but these will have orange bellies, and flatter heads. Finally, the Brown Watersnake has square blotches, and an odd head-shape with a droopy face.

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​Maps and External Sources

Known and predicted ranges

***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.***

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iNat Observations