Common Watersnake (Northern Watersnake)
Nerodia sipedon • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: sipedon
Widespread across North America, occurring throughout the central and eastern United States from southern Canada down to the Gulf Coast and as far west as Colorado.
Look up Common Watersnake (Northern Watersnake) in the Snake Encyclopedia →Venomous Status
Non-venomous; lacks fangs and venom glands.
Danger Level
Low Risk; they are harmless to humans but can be highly defensive. They may bite repeatedly and secrete a foul-smelling musk if handled.
Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: sipedon
Conservation
IUCN Red List: Least Concern. Generally abundant, though habitat destruction and persecution by humans (mistaken for Cottonmouths) are local threats.
Physical Description
Heavy-bodied snake with highly keeled scales. Coloration ranges from grayish-brown to dark brown with darker crossbands or blotches that are widest on the back. The head is relatively flat and slightly distinct from the neck. Pupils are round.
Size & Dimensions
Specimen appears to be an adult, approximately 24-36 inches (61-91 cm). Species typically ranges from 24 to 42 inches, with a maximum record of about 55 inches.
Habitat
Highly aquatic; found in a variety of freshwater habitats including lakes, ponds, marshes, rivers, speed drainage ditches, and streams. Often seen basking on rocks or logs near the water's edge.
Behavior & Temperament
Diurnal and crepuscular; active hunters that are quick to retreat into water. When cornered, they flatten their bodies and heads to appear larger and will strike vigorously.
Diet & Feeding
Primarily piscivorous and carnivorous; feeds on fish, frogs, salamanders, and occasionally small mammals or birds. They use an active foraging strategy, grabbing prey and swallowing it alive.
Reproduction
Viviparous (gives birth to live young). Mating occurs in spring; females give birth to 15-30 young (record up to 99) in late summer or early autumn.
Venom Profile
Non-venomous - no medically significant venom. However, their saliva contains mild anticoagulants to assist in handling slippery prey.
Look-alikes
Commonly confused with the venomous Cottonmouth (Agkistrodon piscivorus). Distinguishable by round pupils (Cottonmouths have vertical slits), absence of heat-pitting, and labial scales with vertical black lines.
Conservation Status
IUCN Red List: Least Concern. Generally abundant, though habitat destruction and persecution by humans (mistaken for Cottonmouths) are local threats.
Cultural Significance
Ecologically vital as both a predator of fish and prey for larger birds and mammals. Often unfairly maligned due to its resemblance to more dangerous species.
Notable Features
Features extremely keeled scales giving it a very rough texture. Unique among many colubrids for its live-bearing reproductive strategy and its ability to remain submerged for extended periods.