Common Watersnake
Nerodia sipedon • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
Widespread across North America, ranging from southern Ontario and Quebec in Canada, through the Eastern and Central United States, and as far south as Texas and Florida.
Look up Common Watersnake in the Snake Encyclopedia →Venomous Status
Non-venomous (no fangs)
Danger Level
Harmless; though they are highly defensive and will strike repeatedly if cornered, they lack venom. Bites may cause minor scratches and bleeding due to anticoagulants in saliva.
Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
Conservation
IUCN Least Concern. Common throughout its range, though often killed by humans who mistake it for a venomous species.
Physical Description
Heavy-bodied snake with keeled scales. Coloration consists of dark brown, reddish-brown, or blackish crossbands or blotches on a lighter tan or gray background. The head is flat with large labial scales often marked with vertical dark bars. Pupils are round.
Size & Dimensions
Typical adult range is 24 to 42 inches (61–107 cm); this specimen appears to be a large adult, approximately 30-36 inches in length.
Habitat
Semiaquatic; found in and around freshwater sources such as lakes, ponds, marshes, rivers, and streams. Often seen basking on rocks, logs, or as in this image, man-made structures over water.
Behavior & Temperament
Diurnal and crepuscular; highly active and fast. Known for a 'grumpy' temperament, they will flatten their bodies and heads to look more imposing and readily bite and musk when handled.
Diet & Feeding
Generalist carnivore focusing on aquatic prey including fish, frogs, toads, salamanders, and occasionally large insects or small mammals. They are active hunters that forage along the water's edge.
Reproduction
Viviparous (gives birth to live young) rather than laying eggs. Mating occurs in spring, with litters of 15-30 young born between August and October.
Venom Profile
Non-venomous - no medically significant venom.
Look-alikes
Often confused with the venomous Northern Cottonmouth (Agkistrodon piscivorus). Distinguishable by its round pupils (vs. vertical slits), lack of heat-sensing pits, and different scale patterns on the head.
Conservation Status
IUCN Least Concern. Common throughout its range, though often killed by humans who mistake it for a venomous species.
Cultural Significance
Often maligned due to its resemblance to the Cottonmouth, but plays a crucial role in regulating fish and amphibian populations in wetland ecosystems.
Notable Features
Features vertical dark lines on the labial scales (lip scales) which is a diagnostic feature for many Nerodia species. When threatened, they release a foul-smelling musk from their cloaca.