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#NotesFromTheRiver - Cottonmouth!

Florida Cottonmouth or Water Moccasin
(Agkistrodon piscivorous conanti)

When I was a kid, I once saw a movie (yes, movies did exist way back then!) set in a swampy area that was meant to be Florida, as only Hollywood could depict it. There was a dramatic scene wherein characters were trying to wade through waist-deep black water, and they were attacked--yes, attacked--by several water moccasins at once, and much shouting and snake biting and flinging away of serpents went on. I have no clue what the movie was, who starred in it, or anything else. I can, however, still picture that utterly ridiculous scene, which I knew to be utterly ridiculous even at that point in my life.

Cottonmouths, or water moccasins, as they are also called, do not gang up on groups of people and rush toward them to attack. Nope. For one thing, like all venomous snakes, they do not like to waste their venom on animals they can't swallow. It's meant to be  a way to subdue or kill prey, and is only used for defense when the snake decides it has no other choice. And a collective of snakes who aren't cornered or threatened are not going to swim toward animals way too big to eat and start biting them. That's just not how it works. It does, however, make for the kind of movie that helps instill a bitter hatred of all creatures scaly and legless. Particularly legless. After all, people are often willing to concede that some lizards are cute,  and everyone loves a gecko, especially if they have Australian accents and sell auto insurance.

But sadly, many, many people loathe and fear snakes, leading me to wonder if it really is the lack of legs that does it. I'm sincerely hoping that my #NotesFromTheRiver posts will eventually help some of you (and you know who you are) get past this extreme reaction to what are some of nature's most beautiful and interesting creatures.

Today, we'll learn a bit about one of the more notorious of Florida's snakes, the cottonmouth, or water moccasin. And I chose the pictures above to open with, because they show the typical threat display of this much maligned snake, and that's where the term "cottonmouth" comes from. If you see this pale as cotton, gaping mouth in your path, back away. The snake is clearly saying "Don't tread on me," and it means it.

Lots to tell you about this one, and I think I'll start with identification. For our purposes today, we will be focused on the Florida subspecies, Agkistrodon piscivorous conanti, a large, heavy-bodied snake, reaching lengths of 3 to 6 feet. The Florida cottonmouth is marked slightly differently from other cottonmouth subspecies, and happily for us, this makes it VERY easy to identify. There really is no reason to keep bashing every large, brownish snake swimming in or hanging around our lakes, rivers, and swamps. You can tell at a glance which is the snake you need to worry about. And 99% of the time, you don't need to go bashing that one, either. Just walk away, and you'll be fine. (It is a MYTH that moccasins will chase you. Again, they bite when they are cornered, stepped on, or picked up, as a defensive act, only. They will only move in your direction if you are between them, and the place they need to go. Leave them alone, and they'll give you the same courtesy. Really.)

Juvenile Cottonmouth

Now let's learn to identify the cottonmouth. Take a close look at the markings on this baby. Hmmm. I'm guessing you notice right away that the colorful pattern on this little guy does not in any way resemble the coloring of the two adult snakes pictured above. That's because moccasins start out all bright and beautiful, with varying degrees of reddish brown and tan banding, then gradually grow darker and plainer as they age. (BTW, in snake terminology, stripes run the length of the snake from head to tail. Bands encircle the snake from back to belly.) Since the coloration doesn't remain the same from young snakes to adults, we have to find another way to identify both the juveniles and the adult moccasins. And with our Florida subspecies, this is, as I said, very easy: It's all about the head of the snake.

Young Cottonmouth

This little guy is slightly older than the juvenile in the first picture. Look how much he has darkened up, already, and how indistinct his bands are becoming. He's even lost the bright yellow tail, too, which many baby snakes use as a colorful lure, when trying to catch dinner. Now focus on this guy's head. Notice the wide, dark brown cheek stripe running from his eye toward the back of the head. This is distinctive of all Florida cottonmouths, and is not seen on any other species of snake in the state, venomous or not. It is clearly visible in every phase of a cottonmouth's coloration, as well. In the water . . .

. . . or out.

Dark, nearly solid color body . . .

. . . vivid juvenile coloration . . .

. . . or anything in between, even from a distance.

It's all in that wide, brown cheek stripe.


Now let's take a look at the poor Brown Water Snake (Nerodia taxispilota). I say "poor" because this is a large, heavy bodied, brown snake that is forever being misidentified as a water moccasin, and beaten to smithereens by folks who ought to know better, but don't. (That won't be you, though, right? Because now you'll be able to see the difference, and besides, you would never go snake bashing for no reason, anyway. Would you?)

Brown Water Snake (Nerodia taxispilota)

Look closely at the snake above. It not only has a very distinct pattern of dark rectangles in staggered rows, which it retains from birth through adulthood, but check out that face. Here's a closer look. Check it out again.

Harmless Brown Water Snake

Do you see a wide, brown cheek stripe on this head? Nope. Therefore, this is not a cottonmouth, or water moccasin, or dangerous snake of any sort. Unless you grab it, in which case it will definitely bite the heck out of you with its tiny, sharp teeth. But then so will a squirrel, a bird, or any other wild critter that doesn't want you grabbing it. This snake is NOT venomous, and would really just like to be left alone. So one wonders why brown water snakes so often end up like this one:

This person bashed a harmless brown water snake with his garden rake, because he thought it was a "deadly" water moccasin, and thus had to be destroyed. Folks, this isn't a good way for any snake to end up, but especially one as harmless as a brown water snake. I can clearly see the pattern in this photo, which I'll describe again below, and enough of the head to know exactly what this is. Or was. I realize not all of you will feel as sad as I do when I see things like this, but hopefully most of you understand there was no need for it. Mostly, there's no need for it, even when it IS a moccasin, but this poor snake was just hangin' out, hopin' to catch a fish or two. Almost always, the best course of action when you see a snake you can't identify is to admire it from a distance, and then just walk away.

Here is another picture of the harmless brown water snake, showing its very distinctive pattern.

Brown Water Snake in Typical Pose Along a Riverbank

Notice the distinct dark brown rectangles marching down the center of the snake's back. They are offset along each side by another row of rectangles, placed "in between" the ones on top, or staggered, more or less. It doesn't matter if the snake is four feet long . . .

. . . or just a wee, little guy. That pattern and coloration is exactly the same, and very obvious. (As is that lack of cheek stripe).

Okay, that takes care of the easiest way to tell cottonmouths from any other snake in Florida, spotted on land or in the water. Time now for a few interesting moccasin related facts. This range map is divided up by moccasin subspecies, so you can see that moccasins in general, inhabit most of the southeastern United States. The red area is, of course, for our Florida cottonmouth subspecies.


Cottonmouths eat a wide variety of prey animals, including fish, frogs, snakes, turtles, birds and their eggs, mice, rats, squirrels, and even young alligators. They are even known to eat carrion at times, being opportunists where their meals are concerned which is something quite rare among snakes. The one below has ended up in cottonmouth heaven. A shallow, muddy pond filled with baby catfish. Yum, yum. Oh, and by the way, you see what clearly stands out about this snake, don'tcha? Yep. That bold, brown cheek stripe.

Moccasins, like most if not all pit vipers, bear live young. They can give birth to as many as 16 to 20 at a time, though it's usually less. The young are born fully equipped with venom sacs, and capable of delivering a very unpleasant bite right from the start. Leave the handling of all venomous snakes, no matter how small, to the pros.

An interesting tidbit for you. Female cottonmouths can reproduce without the assistance of males. Yep. This is called parthenogenesis, and does happen. Imagine! I'm not going to go into all the technical details involved in this unusual process. I can only wonder why this would be necessary, and I suspect that like most animals, including human beings, it would not be the preferred method. But that's another topic, altogether.

Cottonmouths Doin' the Dance of Love

Now let's talk about those dreaded snakebites. Moccasin venom is primarily cytotoxic and hemotoxic in nature, though it is a complex mixture, like most snake venom. This means that a bite affects body tissue and blood. Tissue damage, or necrosis, can be severe enough to require amputation, and a bite is certainly something you want to avoid. While moccasin bites are more dangerous than those of copperheads, for instance, deaths are rare. But suffice it to say,  being bitten by a cottonmouth is not a pleasant experience. Therefore, watch where you step and where you put your hands when you are in the swamps, woods, or other areas where snakes are likely to be. This makes common sense, anyway. Don't go poking your hands into holes or under logs. That's just asking for trouble.

Moccasins are often spotted swimming, but contrary to what many people think, all snakes can and do swim at times. And several other species spend a great deal of their time in the water. Therefore, it's reasonable to think you might spot a cottonmouth in any body of water in Florida. I've read many times that moccasins tend to swim with their bodies on top of the water, and non-venomous snakes just hold their heads up. These next three photos seem to support this idea.

Cottonmouth Swimming With Body Above Water Surface

And another one.

Non-venomous Banded Water Snake Swimming With Just Head Above Surface. So far, the books are right.


What's this? A photo of a beautiful and completely non-venomous yellow rat snake, taken by Doug Little, swimming with its body above the water, and thus proving a long held theory of mine: Snakes don't read books.

A few more photos for you, because . . . cool!


And that about wraps this up. Hope you've enjoyed these photos, and have learned a few new things, including how to recognize a Florida cottonmouth. And remember, when out and about, keep your eyes open. You never know what you might see--or what might see you!


Stay tuned for next week's post. Not sure what it will feature yet, but it's certain it will include some great photos.
See you then!


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Guest - Mae Clair on Wednesday, 15 March 2017 16:35

Snakes don't bother me, but seeing those photos with their mouths open....er, not their most photogenic moment, LOL.
That wee little guy is adorable :)

Snakes don't bother me, but seeing those photos with their mouths open....er, not their most photogenic moment, LOL. That wee little guy is adorable :)
Marcia Meara on Wednesday, 15 March 2017 16:39
Gaping mouths!

I know what you mean, but it IS a very effective way to stop people in their tracks, which works well for both the snake and the person. You do NOT want to step on this guy, because he will nail you, and that's a real bad thing. So all in all, a pretty effective warning, I think. And yes, little snakes are so cute. At least to me. Thanks for stopping by today, Mae! Always good to see you here. (Or anywhere! :) )

I know what you mean, but it IS a very effective way to stop people in their tracks, which works well for both the snake and the person. You do NOT want to step on this guy, because he will nail you, and that's a real bad thing. So all in all, a pretty effective warning, I think. And yes, little snakes are so cute. At least to me. Thanks for stopping by today, Mae! Always good to see you here. (Or anywhere! :) )
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