Common Watersnake
Nerodia sipedon • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
Distributed widely across central and eastern North America, from southern Ontario and Quebec in Canada, south to Louisiana and Florida, and as far west as Colorado and Nebraska.
Look up Common Watersnake in the Snake Encyclopedia →Venomous Status
Non-venomous - aglyphous (lacks specialized fangs)
Danger Level
Low Risk - Harmless to humans and pets, although they are highly defensive and will bite if handled or cornered. Bites may bleed profusely due to an anticoagulant in their saliva.
Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
Conservation
IUCN Red List: Least Concern. Generally abundant, though threatened locally by habitat loss and persecution by humans who mistake them for venomous snakes.
Physical Description
Heavy-bodied snake with keeled scales. Coloration is typically brown, grey, or reddish with dark crossbands near the head that break into alternating dorsal and lateral blotches further down the body. In older specimens, the pattern may darken to appear almost solid black or dark brown. The belly is usually white, yellowish, or orange with dark crescent-shaped spots.
Size & Dimensions
The specimen appears to be an adult approximately 2.5 to 3 feet long. Species typically ranges from 24 to 42 inches (61–107 cm), with a record length of about 59 inches.
Habitat
Highly aquatic, found in freshwater habitats including ponds, lakes, rivers, marshes, and swamps. It is often seen basking on rocks, logs, or as in this image, lily pads.
Behavior & Temperament
Diurnal and crepuscular, but active at night in hot weather. They are known for being very 'feisty' or defensive; when threatened, they flatten their bodies to appear larger, strike repeatedly, and release a foul-smelling musk from their cloaca.
Diet & Feeding
Generalist carnivore feeding primarily on fish and amphibians (frogs, toads, salamanders). They use an active foraging strategy, searching underwater or along the shoreline.
Reproduction
Viviparous (gives birth to live young). Mating occurs in spring, and females give birth to 15–30 young (can be up to 100) in late summer or early autumn.
Venom Profile
Non-venomous - no medically significant venom.
Look-alikes
Commonly confused with the venomous Cottonmouth (Agkistrodon piscivorus), but can be distinguished by its round pupils (vs. vertical slits), lack of heat-sensing pits, and more slender head that is not as distinct from the neck as the 'blocky' head of a pit viper.
Conservation Status
IUCN Red List: Least Concern. Generally abundant, though threatened locally by habitat loss and persecution by humans who mistake them for venomous snakes.
Cultural Significance
Often serves as an ecological indicator for wetland health. They play a vital role in the food web as both a predator of fish/frogs and prey for larger birds and mammals. Unfortunately, they are frequently killed by people who misidentify them as Cottonmouths.
Notable Features
Superb swimmers capable of diving and staying submerged for extended periods. They have a unique physiological adaptation allowing them to handle the toxins found in many toad species which are poisonous to other predators.