Northern Water Snake Information & Facts

This snake is super common. I grew up in Pennsylvania near a lake, and I usually saw at least 3-4 of these per day down by the lake. And then at least once a month in school, a kid would come in and brag, "I saw a Copperhead yesterday! OMG!" And I would be an annoyed boy.

The Northern Water Snake - There are many people living in North America who will come across the Northern Water Snake (Nerodia sipedon), but because of its range of colors and fairly large size it is commonly mistaken for other species. The large population of the species does belie the fact that a subspecies of the Northern Water Snake that was exclusive to the area around Lake Erie was under threat of extinction, but has recovered over recent years.

Appearance And Diet
The Northern Water Snake is one of the largest snakes to be found in North America, and the largest examples can grow up to a length of four and a half feet. The snake has quite a heavy body and has quite a large head which is in proportion with the body of the snake. The Northern Water Snake can be found in a variety of colors, but the majority will have bands of brown, black and dark green, although they can also have a sandy or reddish color on the body. As the snakes get older their color will darken, and the older adult snakes will actually have a body that is almost entirely black.

They also enjoy quite a varied diet depending on the species present in their habitat, with some snakes eating small mammals, amphibians, invertebrates and fish. The Northern Water Snake will eat almost any animal that it can find, and is often considered to be a beneficial species because of its preference for eating pest species such as mice. They will often show a preference for hunting in the water at night, catching minnows and other small fish. One interesting aspect about the Northern Water Snake is that while it isn’t venomous, its bite does introduce a small amount of an anticoagulant which prevents the wound from healing properly.

Get a look at the Copperhead and the Cottonmouth, which people often mistake the Northern Water Snake for, because these are all thick-bodied aquatic snakes.

Behavior And Habitat
The Northern Water Snake is not a snake that will actively seek a confrontation with other animals and people, but it is worth noting that they will defend themselves if threatened or picked up. They can deliver a nasty bite that would require medical attention in this instance, and are likely to bite repeatedly unless they are released. They can also release a pungent musk and excrement if threatened, but in reality the snake itself poses very little risk to people as long as they are left alone. They are generally solitary creatures and will live by themselves apart from during the mating season, and also during hibernation where they will often share a nest with other snakes.

The color of the Northern Water Snake means that it is commonly mistaken for the venomous Cottonmouth and the Copperhead, but it behaves very differently. While the venomous species are likely to bare their mouth to a threat, the Northern Water Snake will usually flee into the water rather than confront any direct threat.

As the name of the snake suggests, this is a species that is mainly at home in and around water, and can be found on the banks of lakes and rivers. They do enjoy basking on rocks and exposed areas during the daytime, but are also adept swimmers when they go into the water to hunt during the night. This common species can be found across North America, but are especially common near beaver and muskrat dens where the plants provide plenty of cover which they do prefer. They are also most numerous in south east Canada and in the north eastern states of the USA.

Reproduction And Growth Cycle
The female snakes are usually much larger than their male counterparts, and the mating season will last from April when they emerge from hibernation through until June. The gestation period for the female can vary between three and five months, culminating in a single litter of around thirty live snakes between August and October. The Northern Water Snake doesn’t have any maternal instincts, and these young snakes of around seven to nine inches in length will be immediately left to fend for themselves.

The young snakes will grow quite quickly for the first couple of years, doubling in size by the time they are two years old, when they become sexually mature. From the third year onwards the Northern Water Snake will continue to grow, but at a much slower pace. As they get older, they will also become darker in color. Snakes that have been kept in captivity have been known to live up to ten years, but there is very little evidence about the life span of the Northern Water Snake in the wild.

Although the Northern Water Snake is one of the larger species of snakes in the United States, it does have a number of predators including foxes, opossums, raccoons, snapping turtles and other snakes. Because of the array of predators, they will usually flee into the water at the first sign of a threat.

Below are some other species of snake that may look like a Northern Water Snake:
Copperhead Snake
Cottonmouth Snake
Water Moccasin
Brown Water Snake
Banded Water Snake