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 (Agliphous - lacks specialized venom-delivering fangs)
Danger Level
Harmless/Low Risk. While they are non-venomous, they are famously defensive and will bite repeatedly if handled; their saliva contains an anticoagulant which can cause the bite to bleed more than expected.
Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
Conservation
IUCN Red List: Least Concern. They are stable and abundant, though they face threats from habitat destruction and being frequently mistaken for venomous cottonmouths and killed.
Physical Description
Heavy-bodied with highly keeled scales. Coloration is typically brown, tan, or grayish with dark crossbands near the head that break into alternating dorsal and lateral blotches further down the body. The head is wider than the neck, and the pupils are round.
Size & Dimensions
The specimen in the image appears to be a juvenile or sub-adult, roughly 12-18 inches long. Adults typically range from 24 to 42 inches (61–107 cm); females are significantly larger than males.
Habitat
Highly aquatic; found in ponds, lakes, rivers, canals, and marshes. Usually stays near the water edge, often seen basking on rocks, logs, or overhanging branches. Can range from sea level to mountainous regions.
Behavior & Temperament
Highly defensive when threatened. Common behaviors include flattening the body and head to appear larger, striking repeatedly, and releasing a foul-smelling musk and feces. Primarily diurnal but active at night during hot summer months.
Diet & Feeding
Primarily piscivorous and insectivorous. They eat fish, frogs, salamanders, and occasionally small mammals or birds. They hunt by active foraging along the water's edge or underwater, swallowing prey alive without constriction.
Reproduction
Viviparous (gives birth to live young). Breeding occurs in the spring, and a single female can give birth to a litter of 15 to 30 young in late summer or early autumn.
Venom Profile
Non-venomous - no medically significant venom.
Look-alikes
Commonly confused with the Northern Cottonmouth (Agkistrodon piscivorus). Distinct from Cottonmouths by their round pupils (vs. vertical), lack of heat-pits, labial scales with dark vertical lines, and a more slender tail.
Conservation Status
IUCN Red List: Least Concern. They are stable and abundant, though they face threats from habitat destruction and being frequently mistaken for venomous cottonmouths and killed.
Cultural Significance
Often unfairly persecuted due to their resemblance to venomous species. They play a critical ecological role in controlling fish and amphibian populations and serve as a food source for larger predators like herons and hawks.
Notable Features
Features highly keeled scales which give the snake a rough texture and matte appearance. They are excellent swimmers and can remain submerged for extended periods while hunting or hiding.