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.