The Minnesota Vikings’ glassy new stadium will be studied to see how deadly it is for migrating birds.

The operators of the stadium, which opens this summer, said the National Audubon Society and Audubon Minnesota will join the University of Minnesota and Oklahoma State University to study bird deaths from collisions with the stadium. The work is to begin in spring 2017 and cover four migratory seasons, with results to be released in 2019.

The Star Tribune, which first reported the study, said  it would cost $300,000.

Environmentalists had called for bird-safe glass to be used on the stadium, which lies along the Mississippi River flyway, but the idea was rejected.