It is hard to imagine a snake with a worse reputation than the water moccasin or “cottonmouth": Few serpents are more maligned and mistreated in the southeastern United States than this pit viper. Their negative reputation stretches across the country, well beyond their natural range. People tell erroneous stories of seeing “water moccasins” in Maine and even California.
Much of the ill-will toward cottonmouths probably stems from the fact that they do not usually crawl away when approached. When confronted, they will often stand their ground, vibrate their tails and pop their mouths open revealing a white interior. These behaviors are in stark contrast to many other species of snakes that will flee at the slightest provocation. Unfortunately, even the harmless water snakes that occupy the same habitat are often shot, chopped to pieces, or dispatched by other methods because they resemble water moccasins.
Even though many people will tell you how dangerous cottonmouths are, we have found that these snakes will only bite for protection and food acquisition. Many years ago, I worked on a study with Dr. Whit Gibbons at Savannah River Ecology Lab to test just how these snakes behave when encountered in the field. The test involved a series of procedures including stepping near a cottonmouth, stepping lightly on the same snake’s back (wearing snake boots), and finally picking up the snake with a mechanical hand. The findings surprised all of us. The snakes almost never bit when stepped on and only bit about a third of the time when grasped by the fake hand. The bite from any of our native pit vipers can be very serious, requiring immediate medical attention, so don’t try this at home.
Although legitimate bites do happen, the majority of the venomous snakebites result from someone trying to catch or kill a snake.
Cottonmouths are extremely common in the lowcountry. They seem to be less common in the larger ponds and reservoirs, preferring bays, slow-moving streams and swampy areas. These snakes are highly variable in coloration, but are usually plain brown or olive with darker blotches or bands. Cottonmouths average about three feet long and are very stout-bodied. They can be distinguished from harmless water snakes by head shape (cottonmouths having a much larger wedge-shaped head) and elliptical-shaped (cat-like) pupil in the eye. Now, I know what you are thinking-who is going to get that close? It can be difficult to differentiate venomous snakes from non-venomous snakes, so if you are not absolutely certain that it is a harmless species, observe the animal from a distance and leave it alone.
Cottonmouths feed on a variety of animals including frogs, snakes, fish, and even small mammals and birds, using potent venom to kill their prey. They are sometimes seen feeding on dead animals as well. Cottonmouths give birth to 4 to 12 boldly-patterned young in the late summer. Neonates (babies) are born with an almost fluorescent, yellow-tipped tail that they wiggle enticingly to attract frogs and other small animals. This brightly colored appendage is a lure of sorts to attract prey.
Although cottonmouths aren’t destined to win any popularity contests, they serve an important role in our local wetland ecosystems. They prey on many wetland animals and also provide food for alligators, birds, and other predators.