Northern Watersnake
Nerodia sipedon • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
Found across eastern and central North America, ranging from southern Canada down to the Gulf Coast of the United States, and west to Kansas and Nebraska.
Look up Northern Watersnake in the Snake Encyclopedia →Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
Conservation
IUCN Red List status is Least Concern. Populations are generally stable, though local threats include habitat destruction, water pollution, and intentional killing due to misidentification.
Physical Description
Robust body with heavily keeled scales giving a rough texture. Coloration is typically brown, tan, or gray, featuring dark crossbands on the neck and alternating dark blotches down the back and sides. The belly is often marked with distinct crescent-shaped spots or reddish-brown markings. The head is somewhat distinct from the neck with round pupils.
Size & Dimensions
Adult specimen length typically ranges from 75 to 135 cm (30 to 53 inches), with females generally growing larger than males.
Habitat
Inhabits freshwater environments such as streams, rivers, lakes, ponds, marshes, and swamps. They prefer slow-moving or still water with ample basking sites like rocks, logs, or shoreline vegetation.
Diet & Feeding
Consists primarily of fish and amphibians (such as frogs and salamanders), occasionally taking small mammals or birds. They hunt both by active foraging in water and by ambushing prey from shore.
Reproduction
Viviparous (gives birth to live young). Mating occurs in the spring, and females typically give birth to a litter of 8 to 50+ young in late summer or early autumn.
Look-alikes
Frequently confused with venomous cottonmouths (Agkistrodon piscivorus) or copperheads due to similar dark blotched patterns. Distinguished by round pupils (unlike vertical slits in vipers), lack of facial heat-sensing pits, and a more slender, patterned body rather than the blocky head and solid coloration often seen in older cottonmouths.
Conservation Status
IUCN Red List status is Least Concern. Populations are generally stable, though local threats include habitat destruction, water pollution, and intentional killing due to misidentification.
Cultural Significance
Plays a vital role in aquatic ecosystems by helping to regulate fish and amphibian populations. Often misunderstood and persecuted by humans fearing dangerous species.
Notable Features
Known for releasing a strong-smelling musk from cloacal glands and biting readily when handled or cornered. Highly adept swimmers capable of spending prolonged periods in or near water.