Everyone fears the dreaded cottonmouth (Agkistrodon piscivorus), a seemingly ubiquitous venomous snake. Many people use the terms “cottonmouth” and “water moccasin” as synonyms, while others use the latter to designate non-venomous water snakes.
Cottonmouths do not require water to live. They spend more time out of the water (sitting on a log, coiled on a bank, or lying on a limb) than in it, but they hang out in wetlands because that is where most of their preferred food lives. Unlike many snakes that have a rather restricted diet, cottonmouths will eat almost anything. This might sound odd, but it has given them the versatility needed to be quite successful under virtually all conditions they encounter. They are known to eat fish, turtles, birds, eggs, mammals, frogs, tadpoles, carrion of all types, lizards, salamanders, and other snakes, including other cottonmouths. During a drought, biologists were monitoring faunal changes in a swamp near Lafayette. As the water disappeared, species dependent on it also vanished, either following the receding water or dying. When the swamp was completly dry, the only snakes to be found were cottonmouths. They were content to function as terrestrial vipers and were found to be feeding primarily on mice and other cottonmouths. When the rains returned, they expanded their diet.Cottonmouths, as other pit vipers, give live birth. They don’t have a placenta; the young are simply retained inside, each enclosed in a membrane, until they are born. As they leave the mother’s cloaca, the young are fully armed with fangs and venom. Though the adults are dark with some evidence of a pattern when they are wet, the young are orange-brown with hour-glass markings somewhat similar to those of copperheads. Their tail is tipped in yellow and they are known to wave it about in order to attract a meal.
The typical defensive posture is to tilt the head up, open the mouth, and erect the fangs. The mouth interior is whitish, hence the name cottonmouth. Cottonmouths account for the largest number of venomous snake bites in Louisiana due to their abundance and proximity to sportsman and people living in wetlands. Though only rarely fatal with medical treatment, cottonmouth bites are particularly nasty in that gangrene may follow. Always go to a hospital when bitten by a venomous or even possibly venomous snake.