Common Watersnake
Nerodia sipedon • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
Eastern and Central North America, ranging from southern Ontario and Quebec in Canada, south to Louisiana and North Carolina, and west to Colorado and the Dakotas.
Look up Common Watersnake in the Snake Encyclopedia →Venomous Status
Non-venomous (Aglyphous)
Danger Level
Harmless - though they are non-venomous, they can be highly defensive and may bite repeatedly if cornered or handled, often secreting a foul-smelling musk.
Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
Conservation
Least Concern (IUCN). Generally abundant, though often persecuted due to confusion with venomous species.
Physical Description
Heavily built body with strongly keeled scales. Coloration is typically gray, tan, or dark brown with darker crossbands or blotches that are widest on the back. Toward the tail, blotches alternate rather than forming bands. The head is relatively flat and slightly wider than the neck.
Size & Dimensions
The specimen in the image appears to be an adult, approximately 2 to 3 feet in length. The species typically ranges from 24 to 42 inches (61–107 cm), with females being significantly larger than males.
Habitat
Semiaquatic habitats including lakes, ponds, marshes, rivers, and streams. Often found basking on rocks, logs, or low-hanging branches over water.
Behavior & Temperament
Diurnal and crepuscular, though may be active at night in hot weather. Highly defensive temperament; when threatened, they flatten their heads to appear larger, strike vigorously, and release cloacal musk and feces.
Diet & Feeding
Primarily piscivorous, eating various fish and amphibians (frogs, toads, tadpoles). They are active foragers that hunt along the water's edge or underwater.
Reproduction
Viviparous (gives birth to live young). Breeding occurs in spring, with 15 to 30 young typically born in late summer or early autumn.
Venom Profile
Non-venomous - no medically significant venom.
Look-alikes
Commonly confused with the venomous Northern Cottonmouth (Agkistrodon piscivorus). Distinct from Cottonmouths by their round pupils (vs. vertical slits), lack of a heat-sensing pit, and labial bars (dark vertical lines on the lip scales).
Conservation Status
Least Concern (IUCN). Generally abundant, though often persecuted due to confusion with venomous species.
Cultural Significance
Often misunderstood and feared, they play a vital ecological role in controlling fish and amphibian populations and serve as a prey source for larger predators like herons and snapping turtles.
Notable Features
Their saliva contains an anticoagulant which can cause a bite wound to bleed more profusely than expected for a small laceration. They are excellent swimmers and can remain submerged for extended periods.