Northern Water Snake

Nerodia sipedon

Northern Water Snake

NOWA

Status

The Northern Water Snake is abundant in the mountains and Piedmont regions of its range. North Carolina lists the coastal subspecies Nerodia s. williamengelsi as a species of special concern.

Description

The Northern Water Snake is a large (61–134 cm), stout-bodied watersnake with a variable pattern. It is gray or light brown with a dorsal pattern consisting of dark crossbands anteriorly with alternating dorsal and lateral blotches on the rest of the body. The ventral pattern is a series of black or reddish half moons. Four subspecies are recognized: insularum, pleuralis, sipedon and williamengelsi. This nonvenomous species is commonly confused with the venomous Cottonmouth.

Distribution

Nerodia sipedon ranges from Canada and New England to North Carolina, northwestern South Carolina, northern Georgia, Alabama, northwest Florida, Mississippi, southeastern Louisiana, and the southern uplands westward to Colorado.

Habitat

This common snake occurs in most aquatic habitats within its range. Habitats include rocky streams, farm ponds, beaver ponds, lakes, reservoirs, and rivers. This species is often seen basking on logs or in bushes along the water’s edge. In areas in the Coastal Plain, where this species is sympatric with Nerodia fasciata, it becomes much more habitat specific.

Special Requirements

The Northern Water Snake requires unpolluted waters, usually with fish, and abundant shrubs, logs, and similar basking sites.

Breeding Habits

Nerodia sipedon is ovoviviparous, usually breeding during the spring months; females have 8–50 young during the summer.

Food Habits

Fish are the primary food of this species. Other food items include frogs, tadpoles, and salamanders.

Management Suggestions

Pollution and thermal pollution are detrimental to this species and its prey. Specific management practices are not considered necessary at this time.

Additional References

Blaney and Blaney 1979; King 1987, 1988, 1989; Mushinsky 1979; Schwaner and Mount 1976; Tiebot 1987.