Etched in glass: Markings will protect birds at Fridley nature center

Three thousand square feet of glass walls will frame a new addition at Fridley's Springbrook Nature Center, a design meant to connect the visitors inside to the nature outside. But the glass presents a problem for some of the 127-acre preserve's more permanent inhabitants ­— birds.

Birds often don't see the clear walls and fly into them, to their demise. It's a situation that has drawn much attention 12 miles to the south in Minneapolis, at the site of the new Vikings stadium, which will have about 190,000 square feet of glass.

At Springbrook, the glass will be etched and frosted to keep birds from crashing into it.

"We're trying to balance safety for wildlife, because that is a large part of the project … with the goal of letting people see nature," said Joanna Eckles, coordinator of Audubon Minnesota's Project Bird Safe, a project to reduce the number of birds that are killed through collisions with buildings.

Springbrook planners consulted Eckles because of her bird expertise.

The 8,000-square-foot glass-walled addition will be made to Springbrook's interpretive center, featuring a V-shaped roof in the form of wings and inspired by the preserve's abundance of birds.

More than 250 species of migratory birds travel through Minnesota, and they struggle to recognize buildings when they have glass and lighting, Eckles said.

There are various solutions, including using less glass, but Eckles said most people opt to use some sort of markings, landscape modifications or lighting variations. Etched or frosted glass is often effective because it reduces reflectivity. At Springbrook, the etched glass will have diagonal lines spaced 2 inches apart, and the top of the walls will be frosted.

These steps will cost anywhere from $23,000 to $30,000 and are a part of the budget for the $5.5 million addition, said Doc Smith, the project's construction manager. The construction is the largest piece of an overall $7.6 million upgrade at Springbrook.

By comparison, the Vikings stadium is about a $1 billion project, and the 190,000 square feet of glass walls are more than 60 times what Springbrook's addition will include. The Vikings and Minnesota Sports Facilities Authority have said that etching the glass to make it bird-safe would both hurt the stadium's aesthetics and be too expensive. As a possible solution, 3M is trying to develop a film that would be transparent but also protect the birds.

At Springbrook, Smith said the planners are also making landscape considerations to keep birds from flying into the building, such as putting bird feeders closer to the glass, or on the glass.

Construction on the addition will likely begin in May. The bulk of it will be paid for by $5 million in state bonding that the Legislature approved last year.