Common Watersnake
Nerodia sipedon • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
Extensive throughout North America, specifically eastern and central United States (from Maine to North Carolina and west to Colorado) and southern Canada (Ontario and Quebec).
Look up Common Watersnake in the Snake Encyclopedia →Venomous Status
Non-venomous; lacks fangs and venom glands.
Danger Level
Harmless; though they are famously defensive and will bite repeatedly if handled, their bite lacks venom and poses no significant risk to human life.
Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
Conservation
Least Concern (IUCN); widespread and adaptable, though often killed by humans who mistake them for venomous species.
Physical Description
Heavy-bodied snake with keeled scales. Coloration varies from grey to reddish-brown with dark brown or black crossbands near the head that break into alternating dorsal and lateral blotches further down the body. Pupils are round. Head is slightly distinct from the neck.
Size & Dimensions
Typical adult range is 24-42 inches (61-107 cm); females are significantly larger than males. This specimen appears to be a mature adult approximately 3 feet in length.
Habitat
Semiaquatic; found in or near freshwater sources like rivers, streams, ponds, lakes, and marshes. They utilize rocks, logs, and vegetation for basking. Found from sea level up to mid-elevations.
Behavior & Temperament
Diurnal and crepuscular; highly active. Known for being extremely defensive when cornered, often flattening their heads, striking, and releasing a foul-smelling musk and feces to deter predators.
Diet & Feeding
Active foragers; primarily eat fish, amphibians (frogs, toads, tadpoles), and occasionally small mammals or birds. They swallow prey alive.
Reproduction
Viviparous (gives birth to live young) rather than laying eggs. Litter size ranges from 15 to 30 young on average, typically born in late summer (August to October).
Venom Profile
Non-venomous - no medically significant venom.
Look-alikes
Commonly confused with the venomous Cottonmouth (Agkistrodon piscivorus) and Copperhead (Agkistrodon contortrix). Distinguished from Cottonmouths by round pupils, absence of heat pits, and labial bars (dark lines on the scales along the lip).
Conservation Status
Least Concern (IUCN); widespread and adaptable, though often killed by humans who mistake them for venomous species.
Cultural Significance
Ecologically vital as both a predator of fish/amphibians and prey for larger birds and mammals. They are often victims of human persecution due to being mistaken for venomous 'water moccasins'.
Notable Features
Features vertical dark lines (labial bars) on the scales around the mouth area and a belly marked with reddish half-moons or dark speckles. Their anticoagulant saliva can cause excessive bleeding from a bite, though it is not dangerous.