Common Watersnake
Nerodia sipedon • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
Venomous Status
Non-venomous
Danger Level
Low Risk; though they are non-venomous, they are famously defensive and will bite repeatedly if handled, often producing minor lacerations due to sharp teeth and anticoagulants in their saliva.
Geographic Range
Common across North America, ranging from southern Ontario and Quebec in Canada throughout the eastern and central United States, as far south as North Carolina and as far west as Colorado.
Conservation Status
IUCN Red List: Least Concern. Populations are stable, though they face threats from habitat destruction and being frequently mistaken for venomous Cottonmouths and killed.
Physical Description
Heavy-bodied with strongly keeled scales. Coloration is typically dark brown, tan, or grayish with reddish-brown to black crossbands near the head that break into alternating dorsal and lateral blotches further down the body. The head is relatively flat and wide with round pupils.
Size & Dimensions
The specimen in the image appears to be an adult, approximately 24-36 inches (60-90 cm). The species typically ranges from 24 to 42 inches, with a maximum record of about 53 inches.
Habitat
Highly aquatic; found in freshwater lakes, rivers, streams, ponds, and marshes. Often seen basking on rocks, logs, or structures like wooden stairs near water. Ranges from sea level to mid-elevations in the Appalachian Mountains.
Behavior & Temperament
Extremely defensive when threatened; they often flatten their heads, hiss, and strike. They may also release a foul-smelling musk and cloacal contents. Primarily diurnal but active at night during hot summer months.
Diet & Feeding
Generalist carnivore focusing on aquatic prey. Feeds on fish, frogs, toads, tadpoles, and occasionally small mammals or birds. They use an active foraging strategy, swallowing prey alive rather than constricting.
Reproduction
Viviparous (gives birth to live young). Mating occurs in spring, and females give birth to 15-30 young in late summer or early autumn. There is no parental care after birth.
Venom Profile
Venom Type
Non-venomous - no medically significant venom.
AI-generated — see a qualified source if acting on this. For any snakebite, call emergency services immediately.
Look-alikes
Commonly confused with the Northern Cottonmouth (Agkistrodon piscivorus). Distinguishable by horizontal labial bars on the jaw, round pupils (Cottonmouths have vertical slits), and lack of a heat-sensing pit between the eye and nostril.
Conservation Status
IUCN Red List: Least Concern. Populations are stable, though they face threats from habitat destruction and being frequently mistaken for venomous Cottonmouths and killed.
Cultural Significance
Ecologically vital as both a predator of fish and amphibians and as prey for larger birds and mammals. In many regions, they are a 'misunderstood' species often feared due to their resemblance to venomous snakes.
Notable Features
Features highly keeled (ridged) scales that give the snake a rough texture and matte appearance. They are excellent swimmers and can remain submerged for extended periods while hunting.