Common Watersnake
Nerodia sipedon • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
Common throughout eastern and central North America, ranging from southern Ontario and Quebec down to North Carolina and west to Colorado and the edge of the Mississippi River valley.
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). Population is stable, though they face threats from habitat destruction and being mistaken for venomous Cottonmouths and killed.
Physical Description
Thick-bodied snake with heavily keeled scales. Coloration is typically brown, tan, or grayish with dark crossbands near the head that break into alternating blotches on the back and sides further down the body. The head is flat and slightly wider than the neck; pupils are round.
Size & Dimensions
The specimen in the image appears to be a sub-adult or adult, likely 24–40 inches long. Adults typically range from 24 to 42 inches (61 to 107 cm), with a record length of about 59 inches.
Habitat
Highly aquatic; commonly found near freshwater sources including lakes, ponds, rivers, marshes, and canals. They prefer slow-moving water and utilize basking sites like logs, rocks, or overhanging vegetation.
Diet & Feeding
Primarily piscivorous and carnivorous. They eat fish, frogs, toads, tadpoles, and occasionally large insects or small mammals. They are active hunters that search underwater or wait in ambush.
Reproduction
Viviparous (gives birth to live young). Mating occurs in spring, and females give birth to 15–30 (up to 80) live young in late summer or early autumn.
Look-alikes
Commonly confused with the Northern Cottonmouth (Agkistrodon piscivorus). Distinguishable by round pupils (Cottonmouths have vertical slits), labial bars (vertical lines on the lip scales), and more slender tails. Also confused with Copperheads due to the banding.
Conservation Status
Least Concern (IUCN). Population is stable, though they face threats from habitat destruction and being mistaken for venomous Cottonmouths and killed.
Cultural Significance
Often unfairly persecuted due to their resemblance to venomous species. Ecologically, they are vital for controlling fish and amphibian populations and serve as a food source for larger predators like herons.
Notable Features
Features heavily keeled scales that feel rough to the touch. It has a triangular head shape when defensive that often leads to misidentification as a pit viper despite being a harmless colubrid.