Monday, May 21, 2012

Northern Watersnake

Northern Watersnakes (Nerodia Sipedon Sipedon) are large native watersnakes occurring throughout Missouri.These are the most common of all the species of Nerodia found in Missouri. They are found in numerous habitats, including ponds, lakes, rivers, sloughs, wetlands, marshes and drainage ditches.

This species may be active during the day or at night and are often seen basking on logs or exposed rocks within the water. They will also climb trees overhanging the water and rest. Like most watersnakes they will feed on a wide variety of aquatic prey including fish, tadpoles, crawdads, and frogs. They will also eat birds and small mammals that wonder near the water. They slither around the waters edge hunting for potential food.

(Eating huge catfish)

At the refuge they drained a bunch of the water to create mudflats for the shorebirds. When the water poured out of the drain into the spillway numerous fish were forced out as well. As the water retreated it left behind numerous dead fish. Vultures, snapping turtles, raccoons, possums and other predators took full advantage of the free food. The watersnakes were even attracted to the odors and consumed their fair share of fish, but it would appear this particular snake is sizing up a fish that is way more than he can tackle.

Their color varies specimen to specimen, and will be banded with brown, reddish or brown-black. They may darken with age and become nearly black. When wet their pattern is much more obvious and they are actually a beautifully marked snake. They typically grow to 4 1/2 feet in length, but I've seen individuals that I know are closer to the 5 foot mark. 

Mating occurs from April to June and often results in massive amounts of snakes congregating in one location. Large females emit a pheromone to attract the smaller males. Several males will approach a female and entwine their body around her. They will jerk spasmodically to stimulate her into breeding. Aggressive, stronger males will win the right to mate and many males may mate with a single female.

(Large mating ball in a drainage pipe at Squaw Creek NWR)

I have been making numerous trips to Squaw Creek NWR since May 4, 2012 when I discovered that the Northern Watersnakes were mating. There have been literally dozens of these snakes all over a spillway at the refuge. I was so excited to witness such a phenomena playing out for me to see. I was back up there this morning (May 21) and they were still there attracting mates. In about 3 to 5 months they will give live birth to as many as 30 offspring. 

(Juvenile Northern Watersnake)

These snakes are often mistaken for Cottonmouths and needlessly killed out of fear. While they are very feisty and aggressive they are harmless. Many people erroneously believe that you can ID a venomous snake based on the shape of the head. Not all venomous snakes have triangular shaped heads, and many non-venomous snakes do. It is not an accurate why to tell a venomous snake from a non-venomous. Just look at the definite diamond-shaped head on this Northern Watersnake, which is another reason it is often mistaken for the cottonmouth.

 I've had them come at me as if to chase me, and stood my ground and they slithered around me to escape. They would prefer to avoid confrontation and go out of their way to escape the presence of humans. If you decide to grab one you will most likely earn a bite for your trouble, or at the very least it will musk you. Musking is extremely nasty and smells horrible. It is a mixture of feces and a musk they produce that is guaranteed to earn the snake some distance and safety from being bothered or eaten by a predator who can smell the terrible odor. Although stinky, they are still preyed upon by raccoons, foxes, coyotes, snapping turtles, opossums and aerial predators like hawks.

A young friend of mine went to the refuge with me the other day and decided to try his hand at catching one of these ornery snakes. He chose a large female and soon discovered how fast and feisty they truly are. It struck at him numerous times and narrowly missed nipping his nose at one point. I admire his fearless nature and love of these animals though.

These snakes are often encountered by people while camping, kayaking, canoeing and fishing. Many are killed and discarded because of their aggressive nature and their similar appearance to the venomous cottonmouth. I would ask that we restrain ourselves and tolerate the presence of these snakes as being an important part of the aquatic habitats they occur in. They perform a service in the form of consuming dead, decaying or sick fish. They will only bite if handled. If you leave them alone they will surely leave you alone. 

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