Common Watersnake
Nerodia sipedon • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
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.
Look up Common Watersnake in the Snake Encyclopedia →Venomous Status
Non-venomous (Aglyphous - lacks specialized venom-delivery fangs)
Danger Level
Harmless / Low Risk. They are not dangerous to humans, though they can be very defensive and will 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
IUCN Red List: Least Concern. No major threats, though often killed by humans who mistake them for venomous Cottonmouths.
Physical Description
The specimen shows a brownish-red or copper-hued head with a heavy-set body. Scales are strongly keeled (rough to the touch). The eyes have round pupils. Bodies typically have dark bands that are wider on the back than the sides, which often darken and look solid in older adults.
Size & Dimensions
The specimen in the photo appears to be an adult, approximately 24-30 inches long. The species typically ranges from 24 to 42 inches (61–107 cm), with females being larger than males.
Habitat
Semi-aquatic. Found near freshwater sources such as ponds, lakes, rivers, marshes, and canals. They prefer basking on logs or rocks (as seen in the photo) near water the edge but will hide in crevices when threatened.
Behavior & Temperament
Diurnal and crepuscular; active during the day basking or foraging at night. They are highly alert and quick to retreat into water. If caught, they are known for a feisty temperament, frequent biting, and musk release as defensive measures.
Diet & Feeding
Primarily piscivorous and carnivorous. They eat small fish, frogs, toads, tadpoles, and occasionally large insects or small mammals. They are active hunters that do not constrict, but lunch and swallow prey alive.
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.
Venom Profile
Non-venomous - no medically significant venom.
Look-alikes
Commonly confused with the venomous Cottonmouth (Agkistrodon piscivorus) and Copperhead (Agkistrodon contortrix). Nerodia has round pupils (vs. vertical slits), lacks heat-sensing pits, and has dark labial (lip) bars.
Conservation Status
IUCN Red List: Least Concern. No major threats, though often killed by humans who mistake them for venomous Cottonmouths.
Cultural Significance
Ecologically significant as a top predator in freshwater aquatic systems, controlling populations of fish and amphibians. They are often victims of unearned fear due to their resemblance to venomous species.
Notable Features
Highly adapted for aquatic life, they can remain submerged for extended periods. Their keeled scales help reduce drag and provide grip on slippery wet rocks.