Lauren Divine first heard that the birds were dying on October 13, 2016, when one of her colleagues stumbled across the corpse of a tufted puffin while walking along a beach on Alaska’s St. Paul Island. The next day: another carcass. Soon, several of the island’s 450 residents started calling in with details of more stranded puffins. Some were already dead. Others were well on their way—emaciated, sick, and unable to fly.
Nestled in the middle of the Bering Sea between Alaska and Russia, St. Paul is the largest of the four Pribilof Islands, which together support more than 2 million seabirds. Dead individuals aren’t uncommon. Divine’s team, which works on environmental issues that affect St. Paul’s Aleut community, would usually expect to find one or two on its monthly beach surveys. But that October, “you couldn’t walk more than a few steps before having to pick up another bird,” she says. “It was pretty apparent that something was really wrong in the environment.”
The team stepped up its surveys, braving biting winds and crashing waves to comb the beaches on all-terrain vehicles. Over the next few months, it located more than 350 bodies, a rate that was about 70 times higher than normal. Stranger still, most of these birds were tufted puffins—a species that very rarely washes up dead. In the previous decade, the team had only ever found six puffin carcasses, and never in the winter months. It seemed that the puffins had become the latest species to experience a mass-mortality event—a large-scale die-off, of a kind that’s becoming more and more common.