Research Could Reduce Impacts of Roads, Bridges, Culverts and Dams on Vulnerable Wildlife

Collaborative project gives decision-makers a powerful tool to address a major challenge for animals in Massachusetts.

NORTHAMPTON, MASS. | January 03, 2013

Which Massachusetts culverts could be widened to provide important habitat access for such wildlife as brook trout and migrating alewife? Where would larger bridges and roadway underpasses help bobcats and black bears get where they need to go, while improving driver safety by potentially reducing vehicle collisions with wildlife?

Now, valuable answers to these questions are easily accessible for the first time—and are already being used by decision-makers—as a result of a collaborative project of the University of Massachusetts Amherst, the Massachusetts Department of Transportation and The Nature Conservancy.

“Roads, bridges, culverts and dams play fundamental economic, public-safety and quality-of-life roles for the people of Massachusetts,” said Scott D. Jackson, extension associate professor in the Department of Environmental Conservation at UMass.

“Unfortunately, they sometimes also create barriers that harm migrating fish and other wildlife that require connected habitat to survive,” said Jackson, one of the lead researchers for the collaborative project. “The fragmentation of this habitat is one of the major challenges faced by Massachusetts wildlife.”

Years in the works, the project, called “Critical Linkages,” provides easily accessible data that can help identify specific locations where changes to important infrastructure—bridges, culverts, roads and dams—would be most effective in providing benefits for wildlife and the habitat on which they rely.

Researchers analyzed 48,859 miles of roads and highways, 26,582 road-stream crossings such as culverts and bridges and 2,467 dams in combination with sophisticated information about wildlife habitat to identify places where changes would have the greatest impact.

Maps and data made available through the recently concluded first phase of the project can be found at The project’s second phase, which will develop a tool to inform transportation and other land-use decisions at regional scale, is underway.

The Massachusetts Department of Transportation has used the information already to prioritize several projects, including the replacement the undersized Route 2 culvert over Hartwell Brook in Charlemont, and the Route 41 bridge over Williams River in West Stockbridge.

“The Department of Transportation’s first responsibility is to provide safe and reliable transportation networks,” said Massachusetts Secretary of Transportation Richard A. Davey, the DOT’s chief executive officer. “Improved stream crossings help us meet these responsibilities by reducing flooding; wildlife crossings can help us by keeping more animals off the road, where they’re in danger and create danger for drivers.”

One of the key findings of “Critical Linkages” researchers was that improvements at a relatively small number of locations—10 percent of those analyzed— would have a disproportionately positive impact on wildlife.

“This is exactly what we would hope for,” Davey said, “a high return on investment from a relatively small number of places, which means an efficient use of public money for transportation.”

Alison Bowden, director of The Nature Conservancy’s freshwater program, said “Critical Linkages” will help Massachusetts address long-standing challenges for animals and for people in a thoughtful, forward-looking and pragmatic way.

“‘Critical Linkages’ will benefit transportation safety and reliability for the people of Massachusetts, while also helping us protect the commonwealth’s incredible natural heritage,” Bowden said. “This project and decision-makers’ commitment to using the information it provides will make Massachusetts a national leader on a crucial issue.”

Retired U.S. Congressman John W. Olver, who represented the 1st District of Massachusetts and secured funding for the project, said the project offers a template for others.

“This is a wonderful example of what can happen when public and private partners with different perspectives and missions bring together their skill and knowledge to tackle an important challenge,” Olver said. “I’m happy to have been able to support this work.”

The Nature Conservancy is a leading conservation organization working around the world to conserve the lands and waters on which all life depends. Visit The Nature Conservancy on the web at To learn about the Conservancy’s global initiatives, visit To keep up with current Conservancy news, follow @nature_press on Twitter.

Contact information

James Miller
Media Relations Manager
The Nature Conservancy in Massachusetts
(857) 600-6603

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