northern watersnake (Nerodia sipedon sipedon)
This is a large aquatic snake, measuring 24–42 in. (61–106.7 cm) in length. It has dark crossbands on the neck and foreparts of the body, and alternating dorsal and lateral blotches on the rest of the body. The dark markings are wider than the spaces between them. There are usually black or reddish half-moons on the belly. The adults tend to darken so that the pattern becomes obscure. Half-moons on the belly may be arranged in a regular pattern, scattered at random, represented by dusky areas, or they may be entirely absent. Nerodia sipedon is often confused in Virginia with the venomous cottonmouth or “water moccasin”. The cottonmouth has broad crossbands that occur along the entire length of the body, a large, angular head, vertical pupils, and a pit between the eye and nostril. In addition, the cottonmouth lacks the half-moons on the venter and occurs only in southeastern Virginia. The northern watersnake emerges from hibernation in late March or April and mates soon thereafter. The young, up to 70 in number, are born live from late August to early October. This snake will usually bite when handled, and it can inflict a painful wound from its long teeth. This species does not vibrate its tail when disturbed, like many other nonvenomous snakes do, as well as some venomous snakes, like the cottonmouth. This trait may be absent from all North American watersnake species.
This snake is found below 1500 meters elevation statewide in Virginia, including several of the barrier islands. The northern watersnake is common in a variety of aquatic habitats, including lakes, ponds, rivers, freshwater and tidal creeks, ditches, swamps, freshwater and brackish marshes, and low wet areas.
This snake is a predator of fish and amphibians, although other prey are sometimes taken. Prey are swallowed alive.