When ground water collected in a old open pit copper mine near Butte, Montana, it created a toxic lake. The sulfuric acid-laced water that resulted is dangerous to migratory birds.
That’s why, for the last thirty years, “waterfowl protection specialists” have been employted to scare the birds away. They use everything from sirens, lasers, propane cannons, drones (both flying and floating) and even fireworks to shoo the birds if and when they land in the water.
One of the most effective ways to spook the birds off the pit, though, is to fire some strategically-placed rounds in the water around them. Enjoy the video.