Common Watersnake
Nerodia sipedon • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
Widely distributed throughout North America, ranging from southern Ontario and Quebec in Canada, through the eastern and central United States, as far south as North Carolina and as far west as Colorado.
Look up Common Watersnake in the Snake Encyclopedia →Venomous Status
Non-venomous
Danger Level
Low Risk. While harmless to humans, they are often defensive when cornered and may bite repeatedly or musk, but they pose no serious health threat.
Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
Conservation
Least Concern (IUCN). Generally abundant throughout their range, though they face local threats from habitat degradation and being killed by humans who mistake them for venomous species.
Physical Description
A thick-bodied snake with heavily keeled scales. Coloration is typically gray, tan, or brownish with darker crossbands or blotches that are wider than the spaces between them. Bands often break into alternating blotches on the mid-body. The belly is usually lighter with reddish-brown half-moons.
Size & Dimensions
Typically 60–100 cm (24–39 inches) in length. Maximum recorded lengths can reach approximately 135 cm (53 inches). The specimen in the image appears to be a mature adult.
Habitat
Semi-aquatic. Found in or near freshwater sources including rivers, lakes, ponds, marshes, and canals. They prefer slow-moving or standing water and are often found basking on rocks, logs, or low-hanging branches.
Behavior & Temperament
Highly defensive when provoked. When threatened, they flatten their heads and bodies to appear larger and will bite readily if handled. They are mostly diurnal but may hunt nocturnally during hot summer months.
Diet & Feeding
Primarily piscivorous and insectivorous. They eat various fish and amphibians (frogs, toads, salamanders). They are active foragers that seize prey and swallow it whole, often utilizing shallow water to corner targets.
Reproduction
Viviparous (gives birth to live young). Breeding occurs in spring, and females give birth to 15 to 30 young (record of 99) 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). To distinguish: Watersnakes have round pupils (Cottonmouths have vertical slits), lack heat-sensing pits, and have labial scales with dark vertical bars.
Conservation Status
Least Concern (IUCN). Generally abundant throughout their range, though they face local threats from habitat degradation and being killed by humans who mistake them for venomous species.
Cultural Significance
Crucial role in freshwater ecosystems by controlling fish and amphibian populations. Often unfairly persecuted due to their resemblance to venomous species and their cantankerous temperament.
Notable Features
Highly adapted for aquatic life with eyes situated toward the top of the head. Their saliva contains anticoagulants that prevent prey's blood from clotting, making even small bites on humans bleed freely.