MINNEAPOLIS (WCCO) — A prominent ornithological group says the forthcoming Vikings stadium will be a serious threat to birds unless its glass is changed.

The Audubon Society said that they are calling on the team and the Minnesota Sports Facilities Authority to modify the stadium’s current specs in order to “make sure it’s not a death trap” for “thousands of migratory birds.”

Joanna Eckles of the Audubon Minnesota says nationally, almost a billion birds die each year flying into buildings.

“When a piece of glass is very reflective. That reflection shows habitats, say trees and bushes, and sky. And birds have no reason to believe that that’s not the real thing,” Eckles said. “We’ve documented about 125 species in Minnesota as victims of window collision, so this is a real issue, and the great thing is it’s preventable.”

Matthew Anderson, the group’s Minnesota executive director, said that the state guidelines require bond-funded projects to protect birds from window collisions, but claimed the team and MSFA recently rejected Audubon’s requests to use a safer type of glass.

“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,” Anderson said. “We know the people of Minnesota do not want their money killing birds.”

A solution is called fritted glass, made by a company in Owatonna, Minn. It’s lined with dots that make the glass visible for the birds.

MSFA did say yes to some bird protection, agreeing to turn off lights after midnight which attract birds during migration periods.

But last week, MSFA told Audubon it would not use the fritted glass.

In a statement to WCCO, MSFA writes: “We were able to adopt operational guidelines used by other downtown office and residential buildings, we were unable to change the design and do not have the budget to include the $1.1 million needed for bird safe glass.”

The Audubon Society is disappointed with the decision. Eckles argues there could be savings in energy costs. The dots also work to keep sunlight out which keeps the building cool.

Eckles said Audubon requested the stadium either meet the state requirement or the national recognized LEED standard for bird safety.

“In the end, they did neither,” she said.

Construction plans call for the new Vikings stadium to feature nearly 200,000 square feet of glass.