The Striped Crayfish Snake (Regina alleni) has always held a special place for me. The reason being it was the first snake that I actually road cruised on my own when I first moved to Florida. It was mid-October and I was asking around about places in the middle of nowhere to drive around for snakes among my college professors. One suggested Corbett Wildlife Management Area, and that evening I was off and cruising about 5 miles of the road in my small sedan (the road itself is something like 20 miles long, but was mostly flooded.) Sure enough, I found three strange snakes in that five mile stretch; all of them Striped Crayfish Snakes.
Over the past seven-or-so years since, they’ve been a regular sight when traversing wetlands to and fro: never abundant, but also seldom absent with enough effort. I’ve often wondered if these snakes are perhaps really abundant and just very cryptic (in layman’s terms: really good at hiding,) or if they are as uncommon in southern Florida as road cruising surveys would suggest. The reason behind this thinking is that their primary food, crayfish (Procambarus alleni and Procambarus phallax, in southern Florida), are extremely abundant. Now, of course, food isn’t the only limiting factor for whether a species is abundant or not – predation, territoriality and a hundred other factors contribute to this. That said, I still always suspected if you could strip away all the vegetation, muck and other composition of a freshwater marsh in the Southeast, you would find a ton of Crayfish Snakes.
Now, I didn’t (nor will I likely) get a chance to do the aforementioned destructive experimentation, but I got close enough recently with the high waters related to Tropical Storm Isaac (see some of the effects here: https://fieldventures.wordpress.com/2012/08/30/tropical-storm-herping/ – this trail is usually high and dry.) With these high waters, I began to notice numbers of DOR (dead on road) Crayfish Snakes around my field site every time I went out. One particular night, I had to check some traps and happened to be on the road at “prime time” where I saw one Crayfish Snake crossing the busy road. So, I stopped the car and went to grab it. I was curious as to whether there might be more out, and I walked 10 feet or so down the road’s shoulder and sure enough: another Crayfish Snake. My dear wife, Beka, was gracious enough to let me walk a ways more, and to even join me in my walk: we ended up getting 21 snakes in about 30 minutes, 10 of which were crayfish snakes.
To be clear: the most crayfish snakes I had gotten in one evening were the three from Corbett seven years prior. I had more than tripled that number: wow! The disappointing part of this Crayfish Snake movement was that I could see it had been going on for many days: fifty or more DOR Crayfish Snakes littered the sides of the road where I walked. So, I aspired to get out again the next night and save as many as I could. I rounded up a posse of 6 other people and we walked the same route as before: this time we turned up 24 snakes, 9 of which were Crayfish Snakes.
What could have caused such a mass migration of snakes? I can only speculate, as I’ve tried asking the snakes in question and gotten only tongue-flicks in response – Crayfish Snakes, like most aquatic snakes, do have to dry out every now and again otherwise they will break out with blisters all over their body: so it may be that they simply ran out of places to dry themselves with the high waters and were forced to take to the roads. It could also have been related to reproduction: of the 19 live Crayfish Snakes caught over those two nights five were heavily gravid, with another several possibly gravid. But really, when it comes down to it, I don’t know why all these Crayfish Snakes are abandoning their aquatic haunts and coming onto roadways; other than I think it has something to do with T.S. Isaac. But this mass movement provided a great opportunity to learn some more about a beautiful and interesting animal.