Common Watersnake
Nerodia sipedon • Order: Squamata, Suborder: Serpentes, Family: Natricidae (or Colubridae), Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
Widespread across central and eastern North America, from southern Canada throughout the eastern United States down to the Gulf Coast and west to Nebraska and Texas.
Look up Common Watersnake in the Snake Encyclopedia →Family
Order: Squamata, Suborder: Serpentes, Family: Natricidae (or Colubridae), Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
Conservation
Least Concern (IUCN Red List). Populations are stable overall, though local populations face threats from habitat destruction, water pollution, and persecution due to misidentification.
Physical Description
Dark grey to brownish body with thick crossbands near the head transitioning into alternating dark blotches further down the dorsum. Strongly keeled dorsal scales give it a rough texture. Heavy-bodied build with a distinct head shape and round pupils.
Size & Dimensions
Specimen appears to be an adult or sub-adult measuring around 2 to 3 feet in visible length. Typical adults range from 24 to 42 inches (60 to 105 cm), with maximum recorded lengths exceeding 4.5 feet (135 cm).
Habitat
Semi-aquatic habitats including ponds, lakes, rivers, streams, marshes, and swamps. Frequently found basking on rocks, logs, or vegetation near water margins from sea level up to moderate elevations.
Diet & Feeding
Primarily feeds on fish, amphibians (frogs, toads, tadpoles), and occasionally small mammals or invertebrates. Active foragers and ambush hunters in and around aquatic environments.
Reproduction
Viviparous (gives birth to live young). Mating occurs in spring, with females giving birth to litters typically ranging from 15 to 30 live young during late summer or early autumn.
Look-alikes
Frequently confused with North American cottonmouths (Agkistrodon piscivorus) due to similar dark coloration and aquatic habits. Watersnakes can be distinguished by their round pupils, lack of facial heat-sensing pits, flat labial scale bands, and strongly keeled scales without distinct supraocular ridges overhang.
Conservation Status
Least Concern (IUCN Red List). Populations are stable overall, though local populations face threats from habitat destruction, water pollution, and persecution due to misidentification.
Cultural Significance
Plays an important ecological role as both a mid-tier predator keeping fish and amphibian populations balanced, and as prey for larger animals like birds of prey, otters, and larger snakes.
Notable Features
Highly adapted for aquatic life, capable of swimming and diving efficiently, flattening its body when threatened, and releasing a pungent musk from its anal glands as a defense mechanism.