University of Minnesota Tests Window Film to Prevent Bird Collisions

The University of Minnesota is experimenting with a reflective film on campus windows in Minneapolis and St. Paul to see whether it can deter birds from colliding with the glass.

A research team from the San Diego Zoo this summer installed video cameras and “shock sensors” at three buildings at the university, the Star Tribune reported.

The university is a magnet for birds because of its closeness to the Mississippi River flyway, a popular migration path for more than 300 species.

Veterinary technician Stephanie Beard has been tracking birds’ collisions with windows on campus. Beard helped point the researchers to what she calls “the most deadly areas on campus for bird collisions.” Those include a three-level skyway on the West Bank of the Minneapolis campus and Coffey and Ruttan halls on the St. Paul campus.

Migrating birds tend to congregate in the fields of food plants and trees that dot the St. Paul agricultural school campus. But navigating the nearby buildings has proved deadly for the birds.

“The windows at Ruttan Hall are particularly large and dangerous,” Beard said, and the scene of “many fatalities” for Nashville warblers, yellowthroat and white-throated sparrows.

The university has tried to warn away birds by plastering bird silhouettes and glitter squares on the windows, and placing plastic owls on ledges. But the crashes keep happening. Beard said the most dangerous time is the fall migration from August to November.

Paquita Hoeck, who is heading the research for the San Diego Zoo, said the hope is that the birds might have better luck spotting the glass if it’s covered with stripes of ultraviolet-reflecting film.

For the experiment, researchers lined some of the windows with a prototype called Anti-Bird Strike film, which was developed by Erickson International with the help of students at the University of Nevada. For comparison, some windows were left untreated.

If a bird crashes into one of those windows, a sensor sends a signal to a video camera to save the footage several seconds before and after the hit, Beard said. “This way we can verify that it was indeed a bird collision that caused the vibration,” she said.

Hoeck said it’s too early to know if the reflecting film is saving birds’ lives. But she said some birds continue to collide with the film-treated windows.

“So if it makes a difference to the birds at all, it’s likely not a very strong one,” Hoeck said, adding she is hopeful researchers eventually will find a solution.