Friday, October 14, 2011

Diamondback Water Snake


On a recent trip to Squaw Creek NWR Cindy and I drove the 10 mile auto tour and discovered this beautiful snake in the road. Upon first seeing the snake her and I thought it was a northern water snake which are very common around here. I posted these pictures to facebook and soon received a correction from a friend and snake expert named Dan Krull that this snake was instead a Diamondback water snake (Nerodia rhombifer rhombifer). Even better,as I had never seen this species before.

Water snakes are notoriously cranky snakes and often strike without warning. This feisty demeanor has earned them a bad reputation. In addition they are often mistaken for the venomous Cottonmouth and needlessly killed. While it is true they very much resemble the cottonmouth and hang out in the same environments and habitats as the cottonmouth the cottonmouth does not occur this far north in Missouri. The likelihood of actually seeing a cottonmouth in NW Missouri is less than 1%. However with global warming, habitat destruction and human persecution that could change over time and their populations could extend further north. This however would be many decades in the future and certainly not a concern now.


The diamondback water snake occurs in southeastern Missouri and over much of the northern, western and eastern parts of the state. It appears to be absent from the ozarks, as their favored habitat of marshes and wetlands are severely lacking in that region. These are the largest of all the water snake species found in Missouri and are very heavy-bodied. They have numerous diamond-shaped markings along their back which earned them their common name. This species has a high variance in color and may be gray, light brown and even a dull yellow. The belly is bright yellow and there are distinctive black lines running vertically through the mouth. This species may reach lengths up to more than 5 feet, but more commonly are in the 4 foot range.


They are active from late March until October. They can be found basking on logs or over hanging branches near water. During the hottest parts of the year they become nocturnal and will be found warming on roadways at night. These snakes can be highly aggressive and if molested will not hestitate to bite. This particular specimen was extremely tolerant and only struck when I placed my foot near its face. It allowed us to take numerous photos and actually had to be coaxed off the road so it would not be hit by the next car to come along. I am always quick to try and remove a snake from the road, as many drivers are not as tolerant of snakes as I am. Many people feel it is their duty to remove all snakes from their region and go out of their way to do so. Many snakes are cruely and needlessly killed on the roads each year.

Like all water snakes this species feeds on frogs, fish and other aquatic creatures. They are considered a bit of an expert at catching catfish and seem to favor that particular variety of fish over all others. Many would argue that if they are eating fish and frogs what good are they? Well they aid in culling out diseased, weakened or even dead fish from an ecosytem. Frogs can and do become over populated and need to have their numbers regulated, and these snakes do an awesome job of that. Out west where the large bullfrog has become invasive and is waging war against native frogs, these water snakes do their part to reduce the number of bullfrogs in those areas.



Water snakes give birth to live young sometime in late August through October. They may have as many as 62 offspring that will measure a foot or more in length. After the first freeze these snakes will return to their hibernation sites. It is at this time these snakes may be found most anywhere. They travel sometimes up to a mile or more to reach those hibernaculums.


12 comments:

  1. Great find and beautiful snake. I have never found one.

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  2. That wide head, evident in the first picture, would have certainly given me pause, making me think it was venomous, until I saw the round pupils.

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  3. I don't know if this species of genus gets in northern utah or not, (i don't know much about snakes at all for that matter)but i found a large black snake along the edge of my grandpa's pond many years ago, definitely was not a garder snake, I never forgot it though! And when I lived in fresno california, those bullfrogs were no joke!

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  4. Thanks David, I know I was super excited when I found out it was a species previously unknown to me. It is always exciting to see any snake, but doubly so when it is something new.

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  5. I know what you mean George, at first glance and from a distance they somewhat resemble rattlesnakes. However many of our non-venomous snakes have that triangular shaped head, that is why I always tell people you can't go by that for identification.

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  6. Jonathan, it sounds like you found a black rat snake at your grandfathers place. They can get quite large and startle a person for sure. I have a friend who lives in CA and she cusses those bullfrogs. They are native here where I live, so they pose little problem here where we have adequate predators to keep them under control.

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  7. There are many types of water snakes found in the world and water snake one of them. A snake could strike you from a distance of half of their body length.

    Water snake

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  8. water snake, thank you for sharing the link with me. Very useful information. I was looking at the chart of water snakes in the USA and noticed for Missouri you had "plain bellied water snake" is that what we refer to as the yellow-bellied water snake(Nerodia erythrogaster flavigaster)? I also didn't see the semi-aquatic Western Mud Snake on your list.

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  9. I encountered one last week, but I didn't know that it was a water snake. Being naive of snakes, I thought it's a cottonmouth or something venomous. That made me become addicted reading and researching about these water snakes. This is the first site I came across: http://www.watersnake.net/

    Good thing they're not really that dangerous. Or else.. :(

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  10. Saw one of these at Indian Camp Creek park in Wentzville/ Moscow Mills area today. Had i not had my 3 kids at a snake and lizard seminar at Busch Wildlife this morning i would have definitely thought this was a venomous snake. However what we learned today the easiest way to identify a venomous snake is not by its head but by diamond shaped eyes, single row of scales on the underside of their tail and if it has fangs or not. There are only 5 venomous snakes found in Missouri. Copperheads, Western Cottonmouth, Western Pygmy Rattlesnake, Eastern Massasauga Rattlesnake and the Timber Rattlesnake.

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  11. I encountered one of the creamy yellow diamondback water snakes while doing landscaping for an apartment complex in Columbia, MO on 8/7/2013. It was lying on tan mulch wrapped around a small bush near very large rocks overlooking a steep bank that drops down to an old creek bed. The creek winds through town near walking/biking trails, businesses, homes and the MO University campus. The snake was sunning at the southern-most bush on a 80 degree day (much cooler than our normal August temp) at 2pm. I had grabbed the bush to remove weeds from the mulch and was surprised as I had not seen snakes on the upper grounds before. I knew there were copperheads in the creek bed below. Had I not seen the diamonds I would have kept working as the snake's color was the same as the mulch. I backed away and the snake eventually disappeared down into the mulch, was seen going down through the rocks toward the creek bed. I am a 60 year old retired RN who likes working outdoors, have lived in the country most of my life, have seen many snakes but the first diamondback water snake! I am amazed and thankful it did not strike at my hands or legs/feet. I will be more cautious and get snake boots.

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  12. These are beautiful snakes, sadly many are killed out of fear and ignorance due to their resemblance to other venomous snakes like the cottonmouth.

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