Northern Water Snake (nonvenomous). Photo credit: J.D. Willson
By J.D. Kleopfer, Herpetologist, VCDGIF
Spring is here and the fishing is heating up. It’s also that time of the year when lots of other critters are heating up and becoming active. Among these critters are water snakes and cottonmouths (aka “water moccasins”). Here are some helpful tips on identification and behavior of these often-misunderstood animals.
The distribution of cottonmouths in Virginia is primarily limited to the southeastern part of the state, particularly the southern regions of Virginia Beach and Chesapeake with isolated populations in Brunswick, Chesterfield, Dinwiddie, Greensville, Prince George, Southampton, Surry, Sussex, and York counties, and the cities of Suffolk and Newport News. On the other hand, water snakes are found statewide in every county and municipality. They also occupy a wider variety of aquatic habitats including lakes and reservoirs, streams, rivers, ditches and even ornamental backyard ponds.
In Virginia, there are three species of water snakes: brown water snake, northern water snake and plain-bellied water snake. The northern water snake being the most widely distributed and the brown water snake the largest, which can reach a length of nearly 6 feet. Of the three species, the northern water snake is by far the most misidentified as a cottonmouth.
Northern water snakes are brown to gray with varying amounts of red, yellow and white. The body is thick and robust with several blotches and crossbands on the back. Although the head is rounded in shape, they will often flatten their head as a defensive response giving it a more “diamond-shaped” appearance. Northern cottonmouths are also a heavy-bodied snake; however, their coloration is darker green to almost black with several dark brown to black hourglass-shaped bands. The head is flattened and angular in appearance. Another common way to identify cottonmouths from water snakes is how they swim. Unlike water snakes that swim with their body just below the surface, cottonmouths float on the water. However, other species of nonvenomous snake, such as the eastern hog-nosed snake, will also float on the water.
Although cottonmouths put on a well-known defensive display known as “mouth gaping”, their aggressive behavior is the stuff of folklore and fish tales. Stories of them attacking boats and water skiers is pure fiction and the imagination of Hollywood movies and television. Those of you that are a little longer in the tooth might remember the famous scene in Lonesome Dove of a cowboy falling into a river and being attacked by a “nest of cottonmouths”. This is probably the beginning of the urban legend of water skiers falling and being attacked by cottonmouths. In fact, cottonmouths are quite reluctant to strike and will usually always choose flight over fight.
Something that many freshwater anglers have experienced is a snake falling from a bush or tree into their boat. This experience can be quite startling to even the most hardcore angler. However, an overwhelming majority of these incidents are harmless water snakes. Brown water snakes and plain-bellied water snakes are particularly notorious for this behavior as they can be found 20-feet up a tree basking on limbs overhanging the water. Being heavy-bodied, cottonmouths are not very good climbers and are seldom seen more than a few feet up in a bush.
A famous naturalist (Clifford Pope) once stated back in the 1850s, “Snakes are first cowards, then bluffers and last of all warriors”. In the end, snakes just want to be left alone.