by Whit Gibbons

January 11, 2015

I received the request via email: “Let me know when you see that glossy strangle a craw.” I replied in the affirmative.

I have not become a spy and this was not code for some hush-hush operation designed to exterminate a criminal mastermind. It was a request from Noel Vick, who had given me the glossy crayfish snake, to let him know if I was able to observe the snake preparing to eat its favorite prey, crawfish – or as some call them, crayfish. I was able to catch several craws that did get strangled, but I never did see it happen. The glossy has now moved on, so I will have to wait to see one in action.

These small, harmless watersnakes have a black, brown or olive green body that has an iridescent sheen when wet. When a glossy crayfish snake captures its favorite prey, it wraps coils around the pinching claws to keep them out of play and proceeds to swallow this dangerous catch backward, tail first. An impressive feat. The snakes are only found where crawfish abound, so their presence is usually a sign of a healthy aquatic environment.

Glossy crayfish snakes deliver several ecological messages. The first is that they are part of our hidden biodiversity. Though seldom seen, they are nonetheless susceptible to pollution and other habitat degradations that adversely affect crayfish and other members of the natural food web. We tend to focus on highly visible species without considering that our actions can also eliminate those we do not see.

Another point is that capture records of glossy crayfish snakes are too scarce to determine their conservation status. Consequently, they are offered no environmental protection because their ecology is too poorly understood for scientists to advise what should be done or not done to protect them. Their geographic range includes a spotty distribution in the coastal plain from Virginia to Texas. Most herpetologists have never seen one in the wild. An out-of-sight, out-of-mind mentality toward conservation is not in the best interest of countless unseen species of native wildlife that are affected by human actions. But to protect them, we must first understand their ecology.

A third lesson is that under the right circumstances a single individual can advance ecological knowledge. For example, Phil Vogrinc, a University of Arkansas student who conducts his thesis research in South Carolina wetlands, has probably caught more glossy crayfish snakes than anyone else in the world. In two summers he captured more than 800 snakes, of which 154 were glossy crayfish snakes. He has gathered more information about the ecology and behavior of the species than herpetologists have done collectively since the snake was first discovered almost 200 years ago.

Such ecological research is not easy. Persistence, perseverance and hard work are essential. Phil’s study involved using “minnow traps,” which are plastic mesh funnels about a foot in length with an opening at either end. Traps are set with a few inches protruding out of the water so that a snake that swims in can still breathe. For days at a time he set out hundreds of minnow traps in wetlands. Walking waist-deep through mucky habitats choked with aquatic vegetation several hours a day, he checked each trap at least once daily – twice if it rained – to ensure traps remained above water. Phil’s major professor, J.D. Willson, used the same technique extensively while studying wetland snakes in the same area during his dissertation research with the University of Georgia a few years earlier.

How many animals out there that are part of our hidden biodiversity are waiting for someone to develop the right technique to study them – and then to persevere in gathering information about them? Only when we understand the ecology of a species can we determine what environmental protection it needs. Fortunately for the glossy crayfish snake, Phil Vogrinc’s research promises to be enlightening about this secretive species.

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