COTTONMOUTH SNAKES, ARE THEY THE BAD BOYS OF THE SOUTH?

by Patricia J. Weaver
(Florence, Alabama)

A cottonmouth snake has a stand-your-ground attitude. With its head back and mouth open, showing the snow-white lining of its mouth makes it an easy snake to identify on land. It’s known as the most aggressive snake in the United States, but is this true? Let’s learn more about the cottonmouth snake and then you can decide for yourself.

The cottonmouth, also known as a water moccasin or trap jaw, is an aquatic, venomous snake. It got the nickname trap jaw because it latches on during a bite, delivering a large dose of venom to its victim.

Cottonmouths are members of the pit-viper family of snakes and cousin to the copperhead and rattlesnake. A pit-viper has facial pits that are sense organs and detect infrared heat. These pits enable the snake to locate its warm blooded prey, even in the dark.

The cottonmouth has a thick muscular body with keeled scales. Keeled scales have a raised ridge down the center that scatters light, causing a dull, non-reflective appearance. Its coloring can vary from shades of deep greens and dull browns to almost black with broad, dimly defined lateral bands. The lighter lateral bands extend across the back and down the side, but not across the belly. Their head is broader than the neck, rectangular in shape and flat on top. Plate-like scales cover the top of the snake’s head and shield its eyes. The cottonmouth’s eyes are camouflaged by a “bandit’s mask”, a dark line running through the eye, bordered above and below by white. Both juvenile and adult snakes share this characteristic. Another interesting trait of the pit-vipers is the pupil of the eye is a catlike, vertical slit whereas most non-venomous snakes have round pupils. The length of an adult snake ranges from 20 to 48 inches long. The record is 74.5 inches. That’s one snake I wouldn’t want to meet.

The cottonmouth gives birth to 1-16 live young during August and September. The young cottonmouth is about 8 to 12 inches long at birth and brightly colored with reddish-brown cross bands on a little brown background. Their cross bands contain dark spots and speckles. Many young cottonmouths are mistaken for copperheads because of their coloring, but as they mature their coloring will darken. From birth they have to catch their own prey because the mother leaves soon after giving birth. Juvenile cottonmouths have bright, sulfur yellow-colored tails that they hold vertical and wiggle the tip like a caterpillar to lure small prey within striking distance.

There are three species: the Eastern Cottonmouth (Agkistrodon piscivorus piscivorus), the Florida Cottonmouth (Agkistrodon piscivorus conanti), and the Western Cottonmouth (Agkistrodon piscivorus leucostoma). The Eastern Cottonmouth is found from the southern counties of Virginia and Kentucky though the southeastern and southern United States. The Western Cottonmouth is found in Texas, Oklahoma, Arkansas, Missouri, Louisiana and Southeastern Kansas. The Florida Cottonmouth is found in Florida, southern Alabama, Mississippi, Georgia, and South Carolina.
The cottonmouth is an ambush predator. When on land the snakes will hold prey in their jaws, inject their venom, then release the victim and wait for the venom to take effect. Once the prey is dead, they swallow it headfirst. In the water, the cottonmouth will swallow its prey whole, without using their venom. This doesn’t mean that they can’t bite and release venom while underwater. They can! The cottonmouth preys on small mammals (like mice and rats), birds, frogs, fish and other snakes. They hunt mainly at night and during the day will sun on a log or tree limb.
The cottonmouth swims with its head out of the water and a good portion of its body visible, which makes it easily identified. It is more buoyant than other water snakes. Their defensive posture identifies them on land. When threatened they will cock their head, showing the white lining of their mouth. If further provoked, they will assume a tight coil and vibrate their tail, imitating the rattlesnake.
The bite of a cottonmouth is serious, because of the severe pain, swelling, discoloration and tissue damage the venom will cause. A cottonmouth’s venom is a hemolytic toxin that attacks the walls of the blood vessels, allowing the venom to escape into the surrounding tissues. Swelling at the bite-site is sometimes so severe that it shuts off circulation to the body part affected by the venom. There have been cases of tissue damage so severe from a cottonmouth’s bite that limbs have had to be amputated.

The second concern of any snakebite is the nasty bacteria the snake has in its mouth. Occasionally, infection can cause more damage than the venom. The effects of the snakebite will subside in a month to six weeks, but there can be permanent tissue loss or nerve damage at the site of the bite. Snakebite victims are not always given antivenins, an antitoxin for venom, because of allergic reactions to the horse protein in the antivenin.

There is a few do’s and don’ts in snakebite first-aid. Keep the effected limb at an even level with the rest of the body, stay calm, try to identify the snake by looking at the color, marking and head shape. Do not try to kill the snake; it could bite you again. Do not use a tourniquet or cut the wound. Do not try to suck out the venom; a cut in your mouth would only place poison closer to your brain and heart. Do not pack the wound in ice; it will not help the swelling. Venomous snakebites are medical emergencies and should get immediate attention.

There are ways to avoid snake bites. Leave the snake alone. People are bitten because they try to kill or pick up a poisonous snake. Wear thick leather boots when hiking in tall grass or rocky locations. Never put your hands and feet in areas that you can’t see.

The cottonmouth is a very dangerous snake and their first reaction to an intruder is defense. They do not usually try to escape but will give the intruder their open mouth and aggressive body language as a warning to stop. If the intruder does not advance the cottonmouth will usually retreat.

Cottonmouths do sometimes advance on boats and climb into them. This is more in territory protection than aggression. They are territorial and will defend their hunting area. The main reason they advance on boaters in boats is because of the attacking movements of the boater. The more you attack a cottonmouth, the more aggressive it will become.

So are cottonmouth snakes the bad boys of the south? The fact their venom is so dangerous would make some people say yes. Their aggressive performance when provoked is scary to see, but they are only defending their territory and food.