In late October, while much of the country was engrossed with the Paul Manafort indictment and Halloween plans, Stella Capoccia was fixated on the number of migrating Snow and Ross’s Geese piling up on the Canadian border. From her base in Butte, Montana, she checked in daily with biologists and naturalists in Canada and Montana, scoured eBird for new reports, and combed through Facebook birding pages for the latest sightings of the garrulous waterfowl, collectively called white geese. The number of birds grew from the thousands, to the tens of thousands, to more than 100,000 by November 2, when a snowstorm spurred them south. Capoccia raised the alarm: The white geese were coming. The previous fall several thousand white geese died when they landed amid a fierce storm on the Berkeley Pit, a former open-pit copper mine on the edge of Butte now designated as part of a Superfund site. Capoccia, a biology professor at Montana Tech, heads an advisory board created last year to devise...