Common Watersnake (alternatively Northern or Plain-bellied Watersnake)
Nerodia sipedon (cf. Nerodia erythrogaster) • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: sipedon
Widespread throughout Central and Eastern North America. In Kansas, species like N. sipedon and N. erythrogaster are common in freshwater systems across the state.
Look up Common Watersnake (alternatively Northern or Plain-bellied Watersnake) in the Snake Encyclopedia →Venomous Status
Non-venomous (Aglyphous - lacks specialized venom-delivering fangs)
Danger Level
Low Risk - Harmless to humans and pets, though they are known to be highly defensive and will bite if handled.
Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: sipedon
Conservation
IUCN Least Concern. Faces threats from habitat loss and intentional killing due to being mistaken for venomous species.
Physical Description
Heavy-bodied snake with strongly keeled scales giving it a rough, matte texture. Coloration is typically dark brown, gray, or olive-black. In older adults (like this specimen), dorsal patterns often fade into a solid dark color. Eyes have round pupils.
Size & Dimensions
Specimen appears to be an adult, approximately 24-40 inches. Species can reach a maximum of about 55 inches.
Habitat
Semiaquatic habitats including ponds, lakes, rivers, marshes, and streams. Often found basking on rocks, logs, or hanging from overhanging vegetation.
Behavior & Temperament
Diurnal and crepuscular; highly defensive when cornered or handled. They often flatten their heads and bodies to appear larger and release a foul-smelling musk if threatened.
Diet & Feeding
Predominantly carnivorous, feeding on fish, amphibians (frogs and toads), and occasionally small mammals or birds. They use active foraging and swallow prey alive.
Reproduction
Viviparous (gives birth to live young). Litter sizes vary from 15 to 60 young, typically born between August and October.
Venom Profile
Non-venomous - no medically significant venom.
Look-alikes
Commonly confused with the Northern Cottonmouth (Agkistrodon piscivorus). Distinct from Cottonmouths by the presence of round pupils, lack of heat-sensing pits, and labial bars (vertical lines on the lip scales).
Conservation Status
IUCN Least Concern. Faces threats from habitat loss and intentional killing due to being mistaken for venomous species.
Cultural Significance
Crucial ecological role as a mid-level predator in freshwater ecosystems, controlling populations of fish and amphibians. Often unfairly persecuted due to misidentification with venomous snakes.
Notable Features
Strongly keeled scales that facilitate swimming and a specialized saliva containing mild anticoagulants to aid in the ingestion of struggling aquatic prey.
Notes
Kansas pond