Identification
The
Northern Water Snake is a medium-sized, stout snake averaging about 30 to 40
inches in length. The coloration of this species is very variable. A typical
pattern is a tan or brown background with a series of very broad black or dark
brown bands on the back and sides. The dark bands are
wider than the light spaces between them. The bands are often complete on the
forward third of the body, but become smaller and alternating towards the tail.
In some individuals and populations, the bands tend to blend together so the
snake appears uniformly dark in color, especially when the skin is dry. The background
color of the belly is often cream-colored,
but is variable, and may even be orange. Superimposed on this background color
are half-moons, or crescents, of darker color. The young have the same markings
as the adults, but they are usually more vivid. Another subspecies of the
Northern Water Snake, the Midland Water Snake, N. s. pleuralis,
is found in the southern half of Indiana. It looks very similar in appearance
to the other subspecies except that the dark bands on its back are narrower
than the lighter spaces between them. Similar species include: Diamondback Water Snake, Copperbelly Water Snake, Cottonmouth.
Distribution and Status
The Northern Water Snake is found statewide, while the Midland Water Snake is generally restricted to the southern two thirds of the state. Both species are considered common in Indiana.
Ecology
The diet of these aquatic snakes consists mainly of various small-sized fish, frogs, toads and salamanders. Both species are almost always found in or adjacent to water. They prefer slow flowing water, but can easily swim and maneuver in strong currents. When disturbed or threatened they can be very aggressive and will strike out. These snakes will sometimes release a musky-smelling substance when they are handled. The Northern Water Snake, found statewide, is sometimes killed because it is mistaken for the venomous cottonmouth, which is only found in the extreme southern portion of the state. While both species prey upon fish, they have little impact on sport fishing. They eat mostly small, slow-moving or injured fish.
Resources
General reference guides
and websites.
Bruce Kingsbury, Director
Center for Reptile and Amphibian Conservation and Management
Science Building
Indiana-Purdue University
2101 East Coliseum Blvd.
Fort Wayne, IN 46805-1499