Northern Watersnake Northern Water Snake; Banded Watersnake; Common Water Snake; Midland Watersnake (ssp. pleuralis)

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Photo of a northern watersnake rearing back in grass on land.

The northern watersnake is Missouri's most common watersnake.

MDC Staff

Other Common Name:

Northern Water Snake; Banded Watersnake; Common Water Snake; Midland Watersnake (ssp. pleuralis)

Family:

Colubridae (nonvenomous snakes) in the order Squamata (lizards and snakes)

Description:

The northern watersnake is a gray to reddish-brown snake with numerous dark brown, reddish-brown, or blackish crossbands along the front third of the body. It is frequently misidentified as a cottonmouth. The bands become blotches in the latter part of the body. The belly is cream-colored or yellowish with numerous black and reddish half-moon markings or spots. As with other watersnake species, the scales along the back have keels, causing the snake to feel rough. For defense, watersnakes bite viciously (but they are not venomous) and secrete a strong-smelling musk from glands at the base of the tail.

Similar species:

The midland watersnake (N. sipedon pleuralis), another subspecies, occurs in the southern third of Missouri. It is tan or reddish brown with brown or reddish-brown bands. Some are orangish with brown markings. It prefers clear, cool, gravel-bed streams. The subspecies overlap and interbreed, so some show traits of both.
Watersnakes are confused with the venomous western cottonmouth and needlessly killed. Cottonmouths are heavier-bodied with a larger, chunky head; have a pit between the nostril and eye; are darker; and have a light line from each eye to the corner of the mouth.

Size:

Length: 24 to 42 inches.

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Northern Watersnake

Like other watersnakes, the northern watersnake can defend itself by biting viciously, but it lacks venom.

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Northern Watersnake

The northern watersnake is gray to reddish brown with dark brown crossbands.

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Northern Watersnake

Northern watersnake coloration and shading can vary quite a bit, depending on the life stage, lighting outside, whether it has recently shed, and (if you're taking a picture) camera settings. This is a young northern watersnake that likely recently shed.

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Northern Watersnake

The northern watersnake, like our other nonvenomous snakes, has round, not vertical, pupils.

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Northern Watersnake

The northern watersnake and other watersnakes actually improve game fishing.

FG-0072_Northern_Water_Snake.mp4

Video of a northern watersnake in the wild.

Northern Watersnake wrapped in a cord

My first snake of the year was a reminder of what litter can do to our ecosystems. DeSoto

Midland Water Snake

Snake swimming away from shoreline. The water makes its reddish color more pronounced.

Midland Water Snake in Lake Springfield Park

User submitted photo

Northern watersnake

A gray snake with red markings on its back makes its way through leaf litter and branches

Northern watersnake near the KATY Trail at Weldon Spring

User submitted photo

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Northern Watersnake Basking on Branches

Northern watersnakes often bask on branches overhanging water or on logs or rocks along the water’s edge.

Habitat and conservation:

This is Missouri’s most common species of watersnake. Individuals bask on branches overhanging water or on logs or rocks along the water’s edge. In hot weather, they are nocturnal. They hide under rocks or other objects along the edge of rivers and ponds. They live in and near a wide variety of aquatic habitats: creeks, rivers, sloughs, ponds, lakes, and swamps.

Foods:

Watersnakes eat fish (mostly nongame species), frogs, tadpoles, toads, and salamanders. Game fish are too agile for watersnakes to catch, unless the fish is injured or diseased.

Distribution in Missouri:

Found throughout the northern and western two-thirds of the state. The midland watersnake subspecies lives in the southern and eastern third. The two overlap and intergrade.

Status:

Locally, this snake is sometimes called “banded water snake” or “common water snake.” More confusing yet, there is another species of watersnake (Nerodia fasciata confluens) that is officially called broad-banded watersnake. Herpetologists create official common names that correspond precisely with scientific names. Because these official common names and the common names used by regular people don’t always agree, it is best to use scientific names when identification must be precise.

Life cycle:

This species is active from early April until October. Courtship and mating occur in the spring, and gestation may last 3-4 months. The young are born live during August and September. A litter can contain 6-66 young, usually averaging 20-25. The young are light gray or tan, contrasting with dark brown or black crossbands and blotches, and at birth they are about 7-10 inches long. Some females may produce a litter every other year.

Human connections:

Watersnakes were formerly killed under the mistaken belief that they ate game fish. In reality, they improve fishing by eating dead or dying fish (preventing the spread of fish diseases), by reducing fish overpopulation, and by providing food for game species (large game fish eat young watersnakes).

Ecosystem connections:

As predators, watersnakes control populations of the animals they consume. But snakes are preyed upon themselves. Their defenseless newborns are eaten by animals ranging from large frogs and fish to other snakes and birds and mammals. Adults are eaten by predatory mammals and birds.