Common Watersnake
Nerodia sipedon
Family: Colubridae (Non-venomous snakes)
Status: Common
Size: 24-40 inches
This is a medium to a large heavy-bodied snake. The background color is gray, brown or tan and is marked with dark brown, red-brown or black transverse blotches, which often fade with age. The underside is distinctive, white with bright red half-moons interspersed irregularly with dark gray speckling.
Common watersnakes are usually found in or close to any permanent waterbody but they prefer clean rivers. Their diet includes crayfish, slow-moving fish and a variety of amphibians. This non-venomous water snake is often mistaken for a cottonmouth (also known as a water moccasin) and is subsequently killed. Cottonmouths, which are venomous, do not occur anywhere near Wisconsin.