Common Watersnake
Nerodia sipedon • Order Squamata, Suborder Serpentes, Family Colubridae, Subfamily Natricinae, Genus Nerodia, Species Nerodia sipedon
Widespread throughout eastern and central North America, ranging from southern Canada south to North Carolina and west to Colorado and Oklahoma.
Look up Common Watersnake in the Snake Encyclopedia →Family
Order Squamata, Suborder Serpentes, Family Colubridae, Subfamily Natricinae, Genus Nerodia, Species Nerodia sipedon
Conservation
Least Concern (IUCN Red List). Populations are generally stable throughout its range, though local declines occur due to habitat destruction, water pollution, and intentional persecution by humans due to misidentification.
Physical Description
Dorsal scales are strongly keeled. Coloration ranges from grayish-brown to dark brown or reddish-brown, with darker crossbands anteriorly that transition into alternating dorsal and lateral blotches further down the body. Darker individuals may appear nearly solid brown or black when dry. The head is distinct from the neck with large eyes featuring round pupils. Vertical labial bars are often present on the upper jaw scales.
Size & Dimensions
Specimen pictured appears to be an adult. Adults typically range from 24 to 42 inches (61 to 107 cm) in total length, though maximum recorded lengths reach over 50 inches (127 cm). Females are significantly larger and heavier than males.
Habitat
Semiaquatic species found in and near freshwater habitats such as rivers, streams, lakes, ponds, marshes, and bogs. Frequently seen basking on rocks, logs, or riprap along water margins.
Diet & Feeding
Carnivorous semiaquatic predator that feeds primarily on fish, frogs, toads, tadpoles, and salamanders. Operates mostly as an active aquatic hunter, catching prey along shoreline shallows and swallowing it alive.
Reproduction
Viviparous (gives birth to live young). Mating occurs in spring (April to May), and females give birth to a litter of 12 to 40 (sometimes up to 90) live young in late summer or early autumn.
Look-alikes
Commonly confused with the Northern Cottonmouth (Agkistrodon piscivorus) where their ranges overlap. Distinguish Nerodia sipedon by its round pupils (vs. vertical slit pupils), lack of facial heat-sensing pits, smooth subcaudal scales, and labial bars on the jaw. Also confused with other watersnake species such as Nerodia erythrogaster and Nerodia rhombifer.
Conservation Status
Least Concern (IUCN Red List). Populations are generally stable throughout its range, though local declines occur due to habitat destruction, water pollution, and intentional persecution by humans due to misidentification.
Cultural Significance
Plays a crucial ecological role in freshwater aquatic ecosystems by regulating populations of fish and amphibians. They are frequently misidentified by humans near bodies of water, leading to unnecessary persecution.
Notable Features
Strongly keeled scales that give the snake a rough texture; adept swimmer and diver; flattened body posture used as a defensive display when cornered; capable of releasing a foul-smelling musk from anal glands when handled or threatened.