Agkistrodon piscivorus leucostoma - Western Cottonmouth
The cottonmouth is a dark, stout, thick-bodied venomous snake. When frightened, the cottonmouth will pop its mouth open. The skin inside its mouth is bright white-and the reason it is called "cottonmouth." Most adults average 30-42 inches (76-106.7 cm) long. They are dark, grayish-brown with little or no markings. Very old cottonmouths may be entirely black. Its broad, flat head distinctly wider than its neck, and it has an elliptical (cat-like) pupil. By day the pupil appears as a narrow slit; at night the pupil is wide and may even look round.
Frogs, fish, smaller snakes (including other cottonmouths), small water birds and small mammals, carrion, and sometimes fish on stringers make up the cottonmouth's diet. Cottonmouths are preyed upon by other snakes and humans. Females reach sexual maturity at three years; males at two years. Mating occurs in the spring. Like other pit vipers, cottonmouths do not lay eggs. Instead the eggs are kept inside the female's body until the eggs are ready to "hatch." Because fertilization and pregnancy are based on the female's physical condition, gestation periods vary from snake to snake and season to season.
Cottonmouths are born from early August until early October. Females bear only three to 12 offspring per litter. Newborn cottonmouths are 6 to 11 inches (15.2 to 28 cm) long. They have brownish or reddish bodies with lines that are wide on the sides and narrow across the back. Cottonmouths are born with yellow or greenish-gray tail tips and come complete with functional fangs and a full supply of venom. DO NOT TOUCH a young cottonmouth! Cottonmouths have a lifespan of less than ten years.
When swimming, the cottonmouth holds its head above water with most of its body barely touching the surface. Cottonmouths are nocturnal, most active at night. The young wiggle their tails so that the tip appears to be a small worm. When small frogs and lizards see the wriggling tail, they think it's something to eat and rush forward to eat it, only to be eaten by the baby cottonmouth. Cottonmouths eat other snakes, including their own kind. The only time more than one cottonmouth would be in the same place at the same time is: 1) mating season, 2) female giving birth, or 3) one cottonmouth is eating another.
Also called "water moccasin," cottonmouths CAN bite underwater, but their prey is fish. If they could not bite underwater, they would starve. Cottonmouths avoid contact with humans or any other possible predator. (All those stories about swarming cottonmouths attacking people are myths!) But like any animal, when threatened, cottonmouths will attack to protect themselves. In some places, especially around woodland ponds, you can find western cottonmouths every few yards. Sometimes, you can smell their musky odor in the air. Heat sensors on either side of the snake's face detect heat and help the cottonmouth to find food.
Western cottonmouths prefer lowland swamps, lakes, rivers, sloughs, irrigation ditches, rice fields and salt marshes, but are not confined to living in moist habitats.
Cottonmouths can be found from southern Illinois south to Alabama, west to Oklahoma and Central Texas
Only 7% of all Texas snakebite cases involve cottonmouths. Throughout the United States, less than 1% of all deaths by snakebite have been caused by cottonmouths. While the odds make it seem unlikely to die from a cottonmouth bite, nonetheless, their venom can still cause severe bleeding and considerable damage to tissue. DO NOT TOUCH and if bitten, seek immediate medical attention!
As our population continues to grow, and wildlife habitat is developed, encounters with venomous snakes are going to occur. Many of these encounters occur around the home, with the result that incidents of bites close to home are statistically high. Keep wood and brush piles, trash dumps and livestock pens as far as possible from the residence. When working in these areas, exercise caution. Never put an arm or leg into something if you cannot see the bottom. Use a flashlight when moving about at night, even in your home yard. Animal burrows make excellent habitat for snakes-don't reach in without first checking.