The current design of the new Vikings stadium in downtown Minneapolis, with lots of giant glass windows, could be a danger to birds that use the nearby Mississippi River as a major fly-way, the Audubon Society says.

The Minnesota chapter of the group says it doesn’t want the billion-dollar stadium — which includes a public subsidy of nearly $500 million — to become a death-trap for birds.

In a statement today, the group says the Vikings and the Minnesota Sports Facilities Authority “have rejected calls to use safer types of glass that could help prevent birds from fatally colliding with the stadium’s huge glass windows as the birds migrate along the Mississippi River corridor each year.”

The Audubon groups says it has worked with building owners for years to protect birds, and while some lighting improvements in the stadium design will be helpful, they can’t get changes made for the stadium glass.

Audubon Minnesota Executive Director Matthew Anderson said:

“We’re talking about a billion dollar stadium here, and the cost to save perhaps thousands of migratory birds  – and make the Vikings a global leader in green stadium design – is about one-tenth of one percent of that. Hundreds of millions of dollars of public money is going to build this stadium, and we know the people of Minnesota do not want their money killing birds. The Vikings recently approved spending millions and millions of additional dollars to make sure the stadium is ‘iconic’ – surely they also want to make sure it’s not a death trap. We’re asking them to change their minds and do the right thing.”