They are active during the day and at night. They are most often seen basking on rocks, stumps, or brush. During the day, they hunt among plants at the water's edge, looking for small fish, frogs, worms, leeches, crayfish, salamanders, small birds and mammals. At night, they concentrate on minnows and other small fish sleeping in shallow water. The Lake Erie water snake subspecies, Nerodia sipedon insularum, was once endangered, but now benefits from the introduction of the round goby, an invasive species, which now comprises up to 90 per cent of its diet.
- N. s. insularum – Lake Erie water snake
- N. s. pleuralis – Midland water snake
- N. s. sipedon – Northern water snake
- N. s. williamengelsi – Carolina water snake
The Northern water snake can grow up to 135 cm (4.4 ft) long. They can be brown, gray, reddish, or brownish-black. They have dark crossbands on their necks and dark stripes and blotches on the rest of their bodies, often leading to misidentification as cottonmouths or copperheads by novices. They darken as they age. Some will become almost completely black. The belly of this snake also varies in color. It can be white, yellow, or gray. Usually it also has reddish or black crescents.
Northern water snakes mate from April through June. They are ovoviviparous (live-bearers), which means they do not lay eggs like most snakes. Instead, they carry them inside their bodies and give birth to baby snakes, each one Template:Convert long. A female may have as many as thirty young at a time. Babies are born between August and October. Mothers do not care for their young; as soon as they are born, they are on their own.
Defense against predatorsEdit
Northern water snakes have many predators, including birds, raccoons, opossums, foxes, snapping turtles, and other snakes. They defend themselves vigorously when they are threatened. If they are picked up by an animal, or person, they will bite repeatedly, as well as release excrement and musk. Their saliva contains a mild anticoagulant, which can cause the bite to bleed more but poses little risk to humans.
Muskrat houses and beaver lodges are good places to find water snakes, which like to hide among the sticks and plant stems. They live near lakes, ponds, marshes, rivers, and canals; just about anywhere there is freshwater.
- Snakes, Davidson College
- Northern Water Snake, Species account on eNature
- Northern Water Snake, Species account from the Iowa Reptile and Amphibian Field Guide
- Northern Water Snake, Natural Resources Canadaes:Nerodia sipedon