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Elizabeth Mohr, St. Paul Pioneer Press, Published March 21 2014

Twin Cities-area county looks into installing special crossing for reptiles and amphibians

STILLWATER, Minn. – There’s no escaping them during the Minnesota spring and fall: turtles, frogs and snakes crossing roads to reach wetlands and breeding grounds on the other side.

Many of them don’t survive the trek.

In Washington County, on the eastern edge of the Twin Cities metro area, there’s a stretch of road that gets so littered with bodies of migrating creatures that residents have asked officials to find a fix.

The one they’ve found isn’t cheap. For a little less than $50,000, the county will install an experimental crossing for herptiles – meaning, reptiles and amphibians – near Big Marine Lake in May Township.

It’s not just about saving the animals but also about increasing public safety, said Wayne Sandberg, deputy director of the county’s Public Works Department.

“One of the problems we have is people stopping to help turtles cross the roads,” he said.

With the help of grant funds, the Washington Conservation District and the county will install the tunnel beneath 170th Street east of Manning Avenue. The road, also known as County Highway 4, cuts through a wetland off the south shore of the lake.

“There are features of this area that make it more likely to have high mortality,” said Christopher Smith, president of the Minnesota Herpetological Society. “To the north of the road, there is a lake and a wetland complex, so a lot of these animals are overwintering in the water, under the ice. And then in the spring, many of the animals are moving to the south to the shallow wetlands where they can lay their eggs.”

Smith and James Landini, a water resource engineer for the conservation district, went to the area last fall.

Landini made five trips to the site and counted a total of about 100 dead animals. Smith said he visited three times and counted about 40.

Smith said several species were documented, including eastern garter snakes, red-bellied snakes, painted turtles, snapping turtles, tiger salamanders, northern leopard frogs and green frogs.

The rare Blanding’s turtle has prompted the most concern, Smith said. The species has been classified as threatened in Minnesota and has been petitioned for federal listing.

Because of the low population numbers, longer lifespan and reproduction cycles of reptiles and amphibians in Minnesota, they warrant enhanced protection efforts, Smith argues.

For example, a female Blanding’s turtle can reproduce for 50 or more years, but isn’t likely to lay eggs until she’s 15 to 20 years old. Few of the eggs or hatchlings survive, but once turtles reach adulthood, they have few natural predators and can live for many years.

The reptile crossing will be built this summer with materials from a German company called Aco Wildlife.

The county received a $10,000 grant from the University of Minnesota’s Local Operational Research Assistance Program (OPERA), which is aimed at transportation projects. And the conservation district received a $37,550 grant from the Minnesota Department of Natural Resources.

Sandberg described the crossing as like a culvert, with a top flush with the pavement and full of holes to allow light and warmth inside, and plastic “wing walls” that guide the animals from the ditch into the tunnel.

“Do they work? Is it a wise use of public dollars? We don’t know the answers, but people often expect us to know,” Sandberg said. That’s why the county sought grant funds for the project and will share its results with interested organizations and officials statewide.

Sandberg said he researched reptile crossings and found a model in Europe, but little in this region.

“The whole idea of this grant, the OPERA funds, is for an agency that does something that nobody else has really done,” he said. “I think one of the things we’ve always valued (in Washington County) is innovation. We’re not just interested in doing the same thing over and over. … And we’re close to a very rural area, so we get a lot of requests to address animal issues. It’s important to the people of the area that we are careful stewards of the wildlife here.”


The Pioneer Press is a media partner with Forum News Service.