Stephen J. Lyons

Dispatch from Illinois' Great Snake Migration

We saw our first snake just moments after we had read Order No. 08‑08 and skirted past the green metal gate placed across La Rue Road in southern Illinois by the U.S. Forest Service.

"The following acts," reads the order, "are prohibited on the road described within the Shawnee National Forest. . . . This includes possessing, parking, operating, or using any motorized vehicle on La Rue Road #345 for 60 consecutive days each spring and fall between the dates of March 15 to May 15, and September 1 to October 30. The road is closed for the protection of migrating reptiles."

"That's a poisonous snake," says U.S.F.S. Biologist Steve Widowski, pointing calmly with a five‑foot, pawpaw walking stick. "It's a little cottonmouth. He's got the triangle head, the black eye stripe. Could be this year's hatch. Copperheads would be a much lighter coppery color. If we see twenty [snakes] today, that's a real good day."

Since 1972, this two‑and‑a‑half-mile gravel road just west of the Mississippi River has been the only road closed in the United States for snake migration. On the western side is swamp and on the eastern side are 350‑foot-tall limestone bluffs. During the spring migration, the snakes make their way down from their dens to the swamps; in the fall they reverse their migration direction.

"These snakes have two very distinct habitat types—the rocky bluffs for hibernation and the lowland areas for foraging—and they must migrate between them," says Chris Phillips, associate research scientist and Curator of Amphibians and Reptiles at the Illinois Natural History Survey and the University of Illinois Museum of Natural History. "It just so happens that a road was built between the two habitats. Roads are often built at the bases of bluffs, so this situation is quite common. In Illinois, there is a road of some kind almost the entire length of the Mississippi River bluffs."

Illinois has more than 138,000 miles of roads statewide and has the third-most miles of freeway in the United States. A common sight on an Illinois freeway is a turtle or snake trying to cross four lanes of traffic. According to the Illinois Natural History Survey's Field Guide to Amphibians and Reptiles of lllinois, in l991, over the course of five fall days, 150 brown snakes were killed on a 1.3‑mile stretch of secondary road.

On this hot day in early October not far from the confluence of the Missouri and the Mississippi rivers, my wife and I have put our trust in the hands of broad‑shouldered Widowski, a former Chicago police officer and ex‑Marine. "I'm not an anti‑snake person, never have been. I really enjoy seeing them. If you've ever studied ecology you know they all have their place.

"You'll want to watch the road edges. That's where they'll be held up. They're going to encounter this gravel and not know what to do. You just want to be 'heads up.' I normally don't prod them. [We'd see more] if we started turning things over. We don't encourage people to do that. We don't want to modify the habitat to see every snake in the world."

Taking no chances, I cleverly position myself in the middle of the road, my wife on the left, Widowski to the right nearest the swamps, where the snakes emerge. The canopy is tangled with pumpkin ash, pin oak, cypress, and native grapevines. Dappled autumn light makes identifying a snake from the black locust seedpods strewn across the road almost impossible, almost as difficult as distinguishing a basking cottonmouth from moss on a log.

Thirty‑five of the state's thirty‑eight snake species have been found in La Rue, including rough greens, diamond‑backed water snakes, speckled kings, and northern copperbellys, and three of Illinois' four poisonous varieties: cottonmouth, copperhead, and the timber rattlesnake, a state endangered species. A common forest snake is the second species we spot—the black ratsnake—which grows to more than eight feet in length. We watch it glide up the slope, a graceful rope of ebony.

Among the less common snakes seen during the migrations, Widowski says, are "The mud snakes. You don't see them during the year because they're underground in the mud, or the swamp. The milk snake is a really pretty snake but you don't see a lot of them—even year‑round."

This small knot of the 280,000‑acre Shawnee National Forest that stretches from the Ohio River in the east to the Mississippi River in the west is a precious ecological gem. In her book Hiking lllinois, Susan Post of the Illinois Natural History Survey writes that in this four‑square‑mile area, 1,200 plant species are found, or 35 percent of all known Illinois plant species. There is also 90 percent of the state's known mammal species, including the rare bobcat and the eastern wood rat. Post calls this part of Illinois "Illinois' biological Garden of Eden."

"Vegetatively, it's the meeting of the north, south, east, and west in the country," Widowski says. "We have species here that are the eastern extent of western species, the western extent of eastern species, the southern of northern, and the northern of southern. It all comes together here."

Before Order No. 08‑08, some locals made sport of how many snakes they could flatten with their vehicles. Collecting for the pet trade was also taking its toll on snake populations. "The term 'amateur herpetologist' scares me," says Widowski. In 1998, concern for maintaining sustainable populations prompted the U.S.F.S. to issue a total ban on collecting throughout the 280,000‑acre Shawnee National Forest. But the fine for a first offense is only $100, and enforcement is sporadic at best. "You can wipe out a population fairly quickly," Widowski says. It's not like they produce hundreds of young. You take a mature female out of the population . . . that's a big impact. Reptiles can be vulnerable certainly to overharvest and malicious killing. Timber rattlers have been overcollected and maliciously killed. People use them for belts and hat bands."

According to the Survey's field guide, a female timber rattlesnake produces six to ten young each year. "Predators of young include hawks, coyotes, skunks, foxes, and common kingsnakes. Most adult mortality is caused by vehicles and wanton killing by humans."

Widowski says that after almost three decades, local residents have accepted the road closure. "It's gone on long enough; I think that the grumbling is over. Originally there was some grumbling. Obviously whenever you close any public road in southern Illinois it creates a stir with local folk, but they've lived with it; and it isn't a big impact on anyone really." The road reopens in the fall in time for waterfowl hunting.

Our hike produces ten sightings, most of those are duckweed‑drenched cottonmouths, some as thick in the girth as my arm. My favorite sighting was the Midland water snake, whose head rose like a periscope through a lily pad to observe us.

Widowski favors the rat snake. "I've got them living in my garage. There's a freezer in there and they like the air from the compressor. My wife gets a little upset because they wrap around the rafters and fall asleep."

 

© Stephen J. Lyons

 
 
 

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