“And that’s when It swam over, mouth open, and charged me!”Everyone who’s into reptiles has heard that same story over and over again. The classic southern fable of the vicious cottonmouth that chased down someone’s cousin and bit them! My name is Phil Wolf, and I’m a herper. And one of my personal quests is debunking the great myths about Cottonmouths.
Cottonmouths or “Water Moccasins,” (as they’re often referred as) are highly venomous pit vipers, native to North America. They don’t charge or chase down humans. They don’t strike down from the trees into boats and they certainly don’t have underwater nests, waiting to gang-up on would-be water skiers. Of the countless times that this author has heard stories of swamp vipers chasing down rednecks, every single one of them could be explained as to why the snake was heading in the direction of the human. But before we start dissecting tall tales, let’s take a look at this amazing species in all of its awesomeness!
Cottonmouths go by many common names. Water moccasin, pond rattler, snap jaw, and water viper, to name a few. My personal favorite, “Swamp Lion”, I think holds the best connotation. Scientifically, cottonmouths are described as, Agkistrodon piscivorus. The etymology is derived from Latin and Ancient Greek. The generic name, Agkistrodon means, “Hooked-tooth.” While the specific name, piscivorus means, “Fish-eater.” A fitting name for the only true semi-aquatic pit viper.
Cottonmouths are true masters of their habitat. They reside in a wide range of sub-tropical ecosystems across the southeastern United States. Swamps, bogs, cypress heads, rivers, lakes and streams make up the majority of their kingdom. This species will even occupy many man-made ponds and golf courses.
There are three subspecies of cottonmouths. From Southeast Virginia down to northern Georgia, is the Eastern Cottonmouth, A. p. piscivorus. These are typically recognized by having darker earth-tones of chocolate brown and faded tan bands. From Alabama, west into eastern Texas, is the Western Cottonmouth, A. p. leucostoma. This species has more pronounced banding of brown and olive drab. And lastly, from South Georgia through the entirety of the Florida peninsula, we have the Florida Cottonmouth, A. p. conanti.
By far the dullest looking of all the moccasins, A. p. conanti is almost entirely black in color, with a lighter underside and brown markings on the face. All adult cottons are heavy bodied with long, thin tails. An average adult will be around three feet long (91cm) but they can get up to and exceed five feet.
Neonate and juvenile cottonmouths are drastically different in appearance from adults. Babies are cryptically banded with rusty-red, chocolate brown, and tan.
Lateral lines of brown and white run horizontally across the face, with the top of the head being copper-ish in color. This copper color can sometimes confuse people, mistaking a baby Cottonmouth for an actual Copperhead, Agkistrodon contortrix. Baby cottons also have a distinct caudal lure. The tip of their tail is brightly colored, highlighter green, yellow, or white. Much like a fisherman uses a brightly colored bait lure, baby cottons undulate their tail tip to attract prey. Everything likes to eat a yellow worm.
Several species of harmless water snakes in the genus Nerodia, mimic the behavior and appearance of the cottonmouth. They have similar banded markings and will oftentimes flatten their heads to appear more “viperish.” This is a common thing in the animal world. However, uneducated humans didn’t get that memo. As a result, water snakes are often confused with cottonmouths and killed by humans.
Having grown up in South Florida, I’ve had the privilege and excitement of working with hundreds of Cottonmouths in my life. And each and every one was a unique and special experience. Smelly, but special. Like most snakes, Cottonmouths are fearful of humans. They view us as a large predator and will do anything they can to evade the situation. Their first line of defense is to musk.
“Ah, the sweet smell of Everglades victory.” The musk of the Cottonmouth is a foul smelling, sticky liquid, that could, quite literally, clear a crowd. Since Cottons have keeled-scales, their musk can permeate in between their scales for a long lasting effect. As rank of a smell as it is, it has a “sharp-sweet” odor to it, that could be used as an indicator that a Cottonmouth is near.
Being semi-aquatic, they’re faster in the water than on land but not as slow as they may appear. Being a stout-bodied snake, they lack the speed and maneuverability to elude most larger predators. So to make up for this lack in agility, they’ve evolved to produce a terrifying display for defense. When threatened or cornered, Cottonmouths will cock their head back and flash open the inside of their mouth, exposing their venom injecting fangs. The inside of their mouth is bone white which contrasts from their dark body color amazingly. This is where they get their infamous moniker from.
If the aggressor is persistent, not being phased by this white warning, then the viper will launch itself towards the aggressor with incredible speed and bite. The strike range of the cottonmouth is usually the length of their body. A four-foot snake, could strike four feet or more.
The most common problem people have when encountering a Cottonmouth, is that the humans know what species it is and will provoke it to try and instigate a “mouth flash.” This is traumatic to the snake and can cause high levels of stress. At the same time, it can push the snake over the edge, to the point that someone gets bitten.
It’s been said that a cottonmouth can track a persons’ movement and will focus on one person in a group, attacking them specifically. This is partially true. Cottonmouths are part of a subfamily of vipers called Crotalinae or pit vipers. This subfamily also consists of Rattlesnakes and most South American vipers. They get the name pit vipers, because of the heat-sensing pits on the sides of their face.
These pits are used to detect infrared thermal radiation, i.e. “Heat Vision.” Much like the thermal camera on a police helicopter, a Cottonmouth can see body heat in total darkness. So when a group of kids surround a Cottonmouth and poke it with a stick, the snake is most likely going to visually lock-on to the first heat source that’s provoking it and follow it as the primary threat to it’s safety. Usually it’s the kid with the stick.
Using this thermal vision to navigate cool waterways and thick terrain, can play a key role in the myth that cottonmouths chase humans. As the stories go, they typically take place on or near water. Whether it’s someone kayaking, a duck hunter standing in waders in a patch of cattails or the poor little boy fishing off the dock at his local pond.
All of these places are typical scenes where a cottonmouth may be found using its thermal vision and senses to find safe and dry land. Being highly aquatic, Cottonmouths have adapted to swimming on the surface of the water. The top half of their body is heavily keeled. While the bottom half is smooth and streamlined. As the snake cuts through the surface of the water, the majority of their mass rides above the meniscus of the water. Thus allowing them to float and use less energy.
Cottons will typically hug the shoreline of a body of water where, coincidentally, the humans are hanging out. What the duck hunter doesn’t see, is that he’s standing in the cottonmouth’s escape route. As for the person in the kayak minding their own business, when the cottonmouth climbs onboard, it’s because the snake is tired from swimming and needs a break on the human’s giant plastic log.
But what about when they chase you down?!? Guess what, they don’t. Cottonmouths don’t chase humans. Typically, when a cottonmouth is seen “chasing” someone, it’s one of two scenarios. Either the snake is attempting to slither to safety, which happens to be in the path of the human. Or the snake is doing what is oftentimes referred to as a “bluff charge.” A bluff charge is when a snake assumes a defensive posture and lunges at the aggressor without actually biting. The snake will “strike” with a closed mouth. And at the last minute, veer to the side slithering away. This is most commonly seen with Australian Elapids.
This is usually a burrow made by a different animal (typically a mammal) and is then used by the vipers as shelter from inclement weather. There have even been reports of mother vipers remaining with their offspring in these dens for a short time postpartum to insure the neonates have a safe and healthy start to life. Yes, that’s right, Cottonmouths give live birth.
Cottonmouths are ovoviviparous. This means their eggs develop and incubate inside the mother. The mother then gives birth to 8-16 live young. Baby cottons are typically 8-10 inches long (20-25cm) and have the full venomous capabilities just like older Agkistrodon.
So what about that venom? When a cottonmouth bites its prey, it injects an appropriate amount of venom to kill the prey item. The venom of Agkistrodon piscivorus is a cocktail of proteins containing haemotoxic, myotoxic and cytotoxic properties.
Now this next part may be a bit shocking for those readers that have made it this far. Cottonmouth’s DON’T have underwater dens used for swarming kids on spring break. Yes, cottons can swim underwater. Yes, they can bite underwater (they eat fish) and no, they don’t actively ball or “school” underwater. There have been several cases where a den of swamp vipers has been found along the shoreline of creeks and streams.
The venom is used primarily for killing and immobilizing prey animals. Certain fibrinogens in the venom promote massive blood clotting. And myotoxic peptides in the venom cause fast diaphragmatic paralysis. Essentially, the envenomated prey item dies from major hemorrhaging, extreme blood clots and circulatory suffocation from paralysis. Certain cytotoxins help to break down the internal organs of the prey item. Literally starting digestion before the snake actually eats its prey.
The venom is produced in glands on top of the snake’s head, just behind the eyes. Ducts carry the venom from the glands down to the snake’s fangs, which are hollow and beveled, like a hypodermic needle. Venom is precious to a snake. It takes time to make and needs to be used sparingly.
As a defense mechanism, it’s a last resort in the viper’s arsenal. This is why cottonmouths are usually reluctant to bite for defense. Why would they waste valuable venom, used for hunting, on a predator? But when all else fails, the venomous bite certainly does the trick.
If you or a friend are bitten by a Cottonmouth, immediately dial 911 and seek medical help. Most Cottonmouth bites are nonfatal. But the venom is still considered lethal! Luckily, this species is native (assuming you live in North America) and most hospitals and zoos have antivenin on hand.
The two main antivenins used for cottonmouth bites are CroFab, (produced using Cottonmouth’s venom) and Antivipmyn. Both are currently produced, but are not cheap. Even with antivenin, bites from cottonmouths can have lasting effects on a human. Scars, permanent muscle damage, and amputations are entirely possible.
Despite the horrors of the Cottonmouth’s venom, these snakes have a bad rap. Too many people for too long have persecuted and mistreated these amazing reptiles. Myth upon myth, tale upon tale. Let’s educate ourselves and others so we can better cohabitate with these amazing animals.
Disclaimer: Nothing written in Herpetoculture Magazine is encouraging or convincing the reader to act in any manner or to perform any action with any venomous species. You as the reader are fully responsible for your actions taken as a result of reading the information provided here.
