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 west as Colorado and as far south as North Carolina.
Look up Common Watersnake in the Snake Encyclopedia →Venomous Status
Non-venomous
Danger Level
Harmless / Low Risk. They are not dangerous to humans but are known for being exceptionally defensive, frequently biting and Muskong (releasing a foul odor) when handled or cornered.
Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
Conservation
IUCN Red List: Least Concern. Generally abundant, though habitat destruction and persecution by humans (mistaken for venomous snakes) are localized threats.
Physical Description
Brown, gray, or brownish-black body with dark crossbands near the head and alternating dark blotches on the back and sides further down the body. Scales are strongly keeled, giving the snake a rough texture. The head is relatively flat and wide, with round pupils.
Size & Dimensions
The specimen in the image appears to be a juvenile, likely 8-12 inches (20-30 cm). Adults typically range from 24 to 42 inches (60-107 cm), with females significantly larger than males.
Habitat
Highly aquatic; thrives in freshwater environments including lakes, ponds, marshes, rivers, and streams. Often found basking on rocks, logs, or overhanging vegetation near the water's edge.
Behavior & Temperament
Diurnal and crepuscular, though nocturnal in high summer. Temperament is highly defensive; they will flatten their heads to look larger and bite repeatedly if they feel threatened. They are excellent swimmers and divers.
Diet & Feeding
Primarily piscivorous and insectivorous; they eat fish, frogs, salamanders, and large invertebrates. They use an active foraging strategy, often searching underwater or along shorelines for prey.
Reproduction
Viviparous (gives birth to live young). Breeding occurs in spring, and litters of 15-30 young (sometimes up to 60) are born in late summer or early autumn.
Venom Profile
Non-venomous - no medically significant venom. However, their saliva contains mild anticoagulants that may cause a bite to bleed more than expected.
Look-alikes
Frequently confused with the venomous Northern Cottonmouth (Agkistrodon piscivorus). Distinguishable by round pupils (vs. elliptical), the absence of a heat-sensing pit, and labial scales with dark vertical bars which are characteristic of Nerodia.
Conservation Status
IUCN Red List: Least Concern. Generally abundant, though habitat destruction and persecution by humans (mistaken for venomous snakes) are localized threats.
Cultural Significance
Ecologically vital for controlling fish and amphibian populations. Often targets of human fear due to their resemblance to cottonmouths, leading to high rates of unnecessary killing.
Notable Features
Known for their ability to remain submerged for extended periods. They possess labial pits that are sensitive to movement and vibration, and their strongly keeled scales help them navigate through slippery aquatic environments.