Green Water Snake
Nerodia floridana
A large, heavy-bodied North American watersnake with plain olive-green coloration, common in swamps and marshes of the southeastern U.S.
- Venomous?
- Non-venomous
- Adult length
- 0.9-1.5 m (3-5 ft)
- Range
- Southeastern United States
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Overview
The Green Water Snake is a large, non-venomous natricine colubrid native to wetlands of the southeastern United States. It is one of the bulkiest members of the genus Nerodia, often mistaken for venomous cottonmouths due to its size and aquatic habits.
Despite its intimidating bulk and defensive display when cornered, this species poses no serious threat to humans; its bite is not medically significant. It plays an important ecological role as a predator of fish and amphibians in freshwater habitats.
How to identify it
- Heavy, thick body reaching over a meter in length
- Uniform olive, brown, or greenish-gray dorsal coloration, often with faint dark blotches most visible in juveniles
- Keeled (ridged) dorsal scales giving a rough texture
- Round pupils and a somewhat blocky head, but narrower than pit vipers
- Cream to yellowish belly, sometimes with dark speckling
Distinguished from cottonmouths by its narrower head, round pupils, and lack of a heat-sensing pit; distinguished from other watersnakes by its larger size and relatively unpatterned adult coloration.
Habitat & range
Inhabits swamps, marshes, lake margins, sluggish rivers, and heavily vegetated backwaters throughout the Coastal Plain from the Carolinas through Florida and along the Gulf Coast to Texas, extending north through the Mississippi River drainage. Favors dense aquatic vegetation such as water hyacinth and lily pads.
Behavior, diet & reproduction
Primarily active by day and at dusk, though it may bask conspicuously on logs or vegetation over water. When threatened it flattens its body, strikes readily, and releases musk, but relies mainly on fleeing into water.
Feeds heavily on fish and amphibians, including tadpoles, frogs, and small catfish, often hunting by probing submerged vegetation. Reproduction is live-bearing (ovoviviparous), with females producing litters of roughly 10-30 young in late summer.
Frequently asked questions
Is the Green Water Snake venomous?
No, it is a completely non-venomous colubrid and poses no serious medical threat to humans.
How big does the Green Water Snake get?
Adults typically reach 0.9-1.5 m (3-5 ft), making it one of the largest watersnakes in North America.
Where is the Green Water Snake found?
It occurs in swamps and marshes of the southeastern United States, from the Carolinas to Texas and up the Mississippi drainage.
Is it often confused with the cottonmouth?
Yes, its large size and aquatic habits lead to frequent confusion with the venomous cottonmouth, though it lacks a heat-sensing pit and has round pupils.
Green Water Snake guides
In-depth guides for identifying and understanding Green Water Snake.
