Common Watersnake
Nerodia sipedon • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
Eastern and central North America, ranging from southern Ontario and Quebec down to North Carolina and west to Colorado and the edge of the Mississippi River.
Look up Common Watersnake in the Snake Encyclopedia →Venomous Status
Non-venomous; lacks fangs or specialized delivery systems.
Danger Level
Harmless; though they are famously defensive and will bite repeatedly if handled, they pose no toxic threat to humans.
Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
Conservation
IUCN Red List: Least Concern. Generally abundant, though often killed due to confusion with venomous species.
Physical Description
Heavy-bodied snake with strongly keeled scales. Color is brownish to grayish with dark crossbands near the head that break into alternating blotches on the back and sides toward the tail. The head is relatively flat and distinct from the neck.
Size & Dimensions
Estimated 60-100 cm (24-40 inches). Adults can reach up to 135 cm (53 inches). This specimen looks to be a mature adult.
Habitat
Highly aquatic; found in lakes, ponds, marshes, rivers, and canals. Frequent basking on rocks, logs, or low-hanging branches above water.
Behavior & Temperament
Diurnal/Crepuscular. Characterized by a very defensive temperament; often flattens its head to appear triangular and releases a foul-smelling musk when threatened.
Diet & Feeding
Mainly piscivorous (fish) and amphibians like frogs, toads, and salamanders. They are active hunters that often forage along the water's edge.
Reproduction
Viviparous (live-bearing); females give birth to 15-30 young on average in late summer or early autumn.
Venom Profile
Non-venomous - no medically significant venom. Saliva contains anticoagulant properties to slow bleeding in aquatic prey.
Look-alikes
Often confused with the venomous Northern Cottonmouth (Agkistrodon piscivorus). Distinct by round pupils (not vertical), lack of heat-sensing pits, and labial scales with dark vertical lines.
Conservation Status
IUCN Red List: Least Concern. Generally abundant, though often killed due to confusion with venomous species.
Cultural Significance
Ecologically vital as both a predator of fish and prey for larger birds and mammals. Often victim to 'mistaken identity' killings by humans who confuse them for venomous snakes.
Notable Features
Excellent swimmers that can dive and stay submerged for extended periods. Their scales are very rough to the touch due to heavy keeling, which may help with grip in aquatic environments.