Identifying NC Venomous Snakes Part1: Cottonmouths (Water Moccasins)

Hello friends,

Now that NC is well into the warm weather (for now at least) you are most likely to have seen at least one snake out and about. I thought I would do a 4 part blog giving you some general clues to identifying NC's venomous snakes. This first part will be about The Eastern Cottonmouth (A.K.A "Water Moccasin").

 

 

So, Eastern Cottonmouths are found around swamps, ponds, tributaries, floodplains, and streams. They generally do not hang around fast moving rivers. Snakes of the Southeast by Whit Gibbons and Mike Dorcas.  They eat a wide range of critters; small mammals, fish, and other reptiles among other things. In fact, I recently saw a Cottonmouth with another snake in its mouth! Cottonmouths are pit vipers that kill prey with venom.

 

 

A good way to identify Cottonmouths is that they are rather impressive, sort of chunky looking snakes.

This chunky look is a good clue to look for. 

 

 

Another way to identify a cottonmouth is the distinctive broad, dark brown stripe along the side of its face. Note* Not all cottonmouths will have a full stripe along the side of face, but it could still be a helpful clue.* It is quite prevalent in the individual pictures above. If you look at the picture and along with seeing the stripe, you may notice the pattern and coloration of this snake. Cottonmouths actually have quite distinctive patterns that stand out from water snakes. According to Amphibians and Reptiles of the Carolinas and Virginia by Jeffrey C. Bean, Alvin L. Braswell, et al.  Their "Dorsal ground color is usually olive or brown, and dark crossbands with light centers constitute the body pattern."  The neonates (babies) are much lighter color with a more eye catching pattern, along with a yellow to yellow-green tail. 

Another thing is the range of the snake: There are records of Cottonmouths in Wake County, but they are rare. 

Cottonmouth Range (
 map comes from herpsofnc.org)

 

 

As you read this, you may be wondering about the eyes. Well, Cottonmouths have cat-like eyes; the term is called elliptical. Water Snakes have round pupils. However, you have to get rather close to the snake to identify the eye, which I would not recommend doing if you have not been trained or your uncomfortable with doing so. Therefore, I am trying to give clues you can use without having to get too close :) 

In addition to the appearance, a way the snake behaves can actually help identify it. The reason a "Water Moccasin" is called Cottonmouth is because if threatened and has no way to escape, it will gape its mouth such as the one pictured above is doing in order to startle the predator and make think twice about eating it. The inside of the mouth is white; hence cottonmouth. So if a water snake does that, then it is probably a cottonmouth, though you may not want to harass the snake to find out ;)  I will say Cottonmouths have a bad rep and really, they are not as aggressive as people think they are. They want to avoid people as much as many people want to avoid them,

 

 

A final note I will make about identifying Cottonmouths is like all pit vipers, they have a pit on each side of their face. According to Snakes of the Southeast by Whit Gibbons and Mike Dorcas It is "A heat-sensitive pit between the eye and nostril." The pit "can detect heat." Gibbons and Dorcas. They use it to hunt prey. But you would have to get pretty close to the snake to see it. 

As far as the water snakes go, I am just posting very brief info and pictures about them. The pictures should give you an idea of how different cottonmouths and water snakes really look. 

Northern Water Snake 

Northern Water Snake Range in NC. Photo from herpsofnc.org

Northern Water Snakes (pictured above) are fairly common in our area. They "typically have alternating bands of reddish brown and lighter brown on the front part of the body, changing to alternating square blotches on the back and sides toward the rear of the body." Snakes of the Southeast. So you are mostly likely to see these guys. I will *note: Water snakes heads are more slender, cigar shaped. Cottonmouths heads are more triangular.*

 

Red-Bellied Water Snake

Range of Red-bellied Water Snake ( Note* orangish-red coloring on belly is key clue for identification) (maps come from herpsofnc.org) (pulled from google)

Brown Water Snake

Range in NC. So, you will not see these guys in Wake County.  Note* Have black square patterns on body, good clue to identifying them*

Banded Water Snake. Note* Have "black, brown, or reddish crossbands...a dark stripe from the eye to the angle of the jaw."* Good clue to identify. source: Amphibians and Reptiles of the Carolinas and Virgina.

Banded Water Snake

So, I know this blog a quite lengthy, but I hope you learn something about Cottonmouths and have an understanding of telling them apart from water snakes. At some point I will do a post on water snakes.  Again, feel free to ask me any questions you may have :)