Mirrors on Bay Bridge Bird Platform?

Good morning, everyone.
If you've ridden an elevated vehicle while driving in the left lane of the eastern span of the bay bridge, heading into the city, you may have noticed a narrow platform attached to the side of the bridge, between the two directions (east lanes and west lanes).
Birds are perched and nesting on this narrow platform. Every few yards there are angled mirrors that the birds likely see themselves in. Some of the mirrors are destroyed, and most of them are dirty.
Does anyone know what the deal with these mirrors are? Some sort of study? I've always been curious.