Thousands of snow geese have perished after landing in an open copper mine in Butte, Montana.
Known as the Berkeley Pit, the site has been a popular tourist attraction since being decommissioned in 1982. During its three-decade run in the mining business, workers extracted nearly 300 million tons of copper, leaving behind a 900-foot deep crevice swelling with floodwater. Inorganic compounds ranging from arsenic to cadmium run rampant within the pit’s liquid contents, many of which pose health risks to the local wildlife.
Harsh November storms likely took a toll on the flock’s migration patterns, causing them to take sudden refuge in the pit. As part of a hazing strategy designed to keep animals away from the water, employees of Atlantic Richfield and Arco tried everything to scare off the birds, whose arrival had been reported earlier by mining company Montana Resources. The program requires workers to monitor the area with spotlights and observation decks, while drones and similar aircraft could be employed as early as 2017 to enhance surveillance efforts.
“We usually see 3,000 to 5,000 in one year,” says environmental affairs manager Mark Thompson. “I can’t underscore enough how many birds were in the Butte area that night. Numbers beyond anything we’ve ever experienced in our 21 years of monitoring by several orders of magnitude.”
Employees managed to save about 90 percent of the flock’s 25,000 individuals, though thousands of birds still fell victim to the pit’s toxicity. Thompson described the area as “700 acres of white birds,” which were strewn across the lake and store parking lots.
Berkeley was the site of a similar incident over 20 years ago. Approximately 350 snow geese were found dead after purportedly consuming lethal substances in the water, which attacked their brains and burned their internal organs. At the time, an autopsy report on two of the birds revealed that “the geese had succumbed to the water, which is acidic enough to liquefy a motorboat’s steel propeller, and to its poisonous mineral contents, principally copper, cadmium and arsenic. In each bird autopsied, the oral cavity, trachea and esophagus, as well as digestive organs like the gizzards and intestines were lined with burns and festering sores.”
The incident has left several residents distraught. Assistant biology professor Stella Capoccia at the University of Montana says locals tried to aid birds that had escaped the pit, only to watch several of them die under what can only be classified as slow and painful circumstances.
“People feel for the birds,” she states with an air of sympathy.
— Audubon Society (@audubonsociety) December 21, 2016
Experts are debating over what could have sparked such a dangerous diversion in the animals’ migratory behavior. One theory suggests that unusually warm weather caused the birds to leave their northern turf somewhat later than usual. Upon reaching Montana, cold snaps had hit their normal stopping points, drawing the birds to the pit which rarely freezes.
The EPA has been managing the site since 1983, monitoring cleanup efforts and working to remove waste material without exposing further hazards. Companies like Montana Resources could face fines of up to $5,000 for every deceased bird due in part to the organization’s policies protecting migratory species.
“The die-off in 1995 should have been a wake-up call,” said Butte government executive Matt Vincent. “Instead, we hit the snooze button.”
The good news is that geese populations have increased significantly over the last 30 years, rising by about 12 million since the 1980s. Birds have even been spotted in regions unknown to house large flocks of migrating geese due to their heightened attempts to find reliable habitats.