Air Date: Week of October 31, 2003

Forest Service road 345 is the only road in the U.S. that closes not for foot traffic, but snake crossings. The road lies smack in the middle of the reptiles’ yearly migration route. Host Steve Curwood talks with herpetologist Scott Ballard about just how heavy this snake traffic can get.

Transcript

CURWOOD: For the past 31 years people driving through Shawnee National Forest in southern Illinois have had to yield – not to pedestrians but to rippling reptiles. Every spring and fall for two months at a time, the U.S. Forest Service closes down Road 345 to let past thousands of migrating snakes. This single-lane gravel road is a major hurdle for snakes leaving their warm weather swamp for winter hibernating dens. Herpetologist Scott Ballard, with the state’s Department of Natural Resources, has walked Road 345 many times to monitor snake crossings and says he’s seen ‘em all.

BALLARD: Mostly, the largest population of snakes down there are water mocassins, also known as cottonmouths, that are venomous. But you can also find things like red milk snakes, western ribbon snakes, copperheads, timber rattlesnakes, earth snakes, brown snakes, king snakes. A number of different species use that road.

CURWOOD: Sounds like a pretty rough crowd.

BALLARD: Yeah, it’s – if you’re faint of heart with snakes it sometimes can be alarming. But even though they use this road quite a bit to migrate across, the road is two and a half mile in length, and if you walk the entire length of that road and see 20 or 30 snakes, you’ve seen a lot. When we were down there a couple weekends ago we were seeing a snake about every 50 feet. And it used to be one of the annual rites of spring for the locals to go down and see how many snakes they could run over in their cars.

CURWOOD: Uh, really.

BALLARD: Mm, hmm. And it’s been a big educational process to educate people in the values of snake conservation.

CURWOOD: And the value of snake conservation, for those who are skeptical listening to you right now?

BALLARD: Well, the best way to describe it to people is one average sized snake can eat up to nine pounds of rats and mice in a year. And nine pounds may not seem like a lot, but it will fill up a pillowcase. So, what I tell people is, every time you kill a snake in your yard or in the woods, it’s almost like dumping a pillow case full of mice out there because that’s pretty much what you did. And mice can carry things like rabies and hanta virus and stuff, so these snakes are actually keeping disease-carrying rodents under control for us.

CURWOOD: Which species tend to cross the road the fastest?

BALLARD: It depends on temperature. I’ve seen the cottonmouths go across the road pretty quick. But if it’s warmer, and that roads really hot and it’s warm on their belly, they’ll move across it faster than if it’s cool and they want to kind of sit on the road and absorb some of that heat for a while.

CURWOOD: Tell me Scott, how often do you help the snakes out themselves get across the road?

BALLARD: Well, if I come across something that I’m doing a mark-recapture study on – like a Mississippi green water snake, we have about 50 of those animals marked down there and we’re trying to determine what their population status is – if I slow the animal down by picking it up, weighing it, determining if it’s a male or female, and then clipping scales, I will then go ahead and put it on the other side of the road that it was headed to.

CURWOOD: Scott Ballard is a herpetologist for the Illinois Department of Natural Resources. Scott, thanks for taking this time with me today.

BALLARD: Well, thank you very much for the opportunity.

CURWOOD: Just ahead: where there’s smoke, there’s a possible health risk. The fallout from the California fires. First, this Note on Emerging Science from Cynthia Graber.