Sure, Mark Martell had heard of birds crashing into man-made structures, such as skyscrapers, wireless communication towers and wind turbines — often fatally.
“It might just be something about the height of the bridge, but I don’t know,” said Martell, director of bird conservation for Audubon Minnesota, after hearing reports that migratory birds were flying into the new Hwy. 61 Hastings bridge or becoming entangled in the cables holding up the $130 million span that connects the historic river town to Washington County. But while environmentalists and bird experts have spent years studying how buildings in urban areas came to be such prolific bird killers, little such research has been done on bridges, Martell said.
He hopes a new study, commissioned by the state Department of Transportation, will change that.
The study will be conducted amid concerns that birds flying back from their wintering grounds in Central and South America may be killed or injured by flying into the bridge, which crosses the avian expressway that is the Mississippi River.
More than 300 species of birds — “millions, if not billions” — fly along the river to and from their wintering grounds, said the park service’s Paul Labovitz, who serves as superintendent of the Mississippi River National River and Recreation Area.
“I watched a flight of pelicans one summer day flying over that took 15 minutes to pass over me,” Labovitz said last week. “So the numbers are staggering.”
MnDOT officials plan to hire an environmental firm to study what makes bridges a threat to birds, which they hope will serve as a template for getting architects to buy into bird-friendly designs in the future.
“At least in the case of buildings, we know that there are some things that can be done to reduce it,” Martell said.
Martell pointed out that the National Park Service had signed off on the 545-foot tied-arch bridge — officials rejected a cable-stayed design in part because it might pose a threat to migrating birds, he said — on the condition that MnDOT undertake another study to better understand the problem of bird strikes on bridges.
The study could cost up to $100,000, Martell said.
“The bottom line is we just don’t know very much about it, so this parks service study is something that interests us and many others,” Martell said.
A MnDOT spokeswoman did not return calls for comment.
“It’s a conversation that’s been going for actually a couple of years, but we’re getting to the point where we’re actually trying to frame what the study’s going to be,” Labovitz said.
“We didn’t have the information to inform this particular bridge design,” Labovitz said,” but we were hoping that this information would inform future projects.”
Audubon Minnesota has partnered with the Building Owners and Managers Association (BOMA), a trade group whose members represent many high-rise buildings in the metro area, on a program called “Lights Out” that encourages building owners to reduce lighting during spring and fall migrations “in an effort to reduce building strikes.” So far, officials said, the program has enlisted nearly 60 tall buildings, including the Wells Fargo Center and the IDS Center.
Something similar should be tried on the Hastings bridge, Martell suggested, whose lights could be dimmed to avoid confusing night-migrating birds, who navigate using the moon and stars and are often attracted by the glow of lighting from buildings.
The U.S. Fish & Wildlife Service estimates that at least 97 million and as many as 976 million birds are killed annually in the United States when they crash into buildings. There are no figures yet on the number of birds killed when they fly into other man-made structures.
He continued: “You have to wonder in 2014 why we don’t know more about this topic.”