"Although the trend is clear, the underlying causes are not. That’s because shorebirds travel thousands of kilometres a year, and encounter so many threats along the way that it is hard to decipher which are the most damaging. Evidence suggests that rapidly changing climate conditions in the Arctic are taking a toll, but that is just one of many offenders."
"At his base camp on the island, Smith looks as if he could have walked out of a tech lab in Silicon Valley — except for the shotgun slung over his shoulder. "
https://www.nature.com/news/what-s-killing-the-world-s-shorebirds-1.21232We don't really know. But it must be a changing climate.

A shotgun for when you fear for your life from polar bears? More likely to piss the bastard off.
Did they count the number of polar bears? Apparently they love birds eggs. They don't have to chase them.
"Researchers say it is now more crucial than ever to understand how conditions in the Arctic are altering breeding and survival. “This is high urgency,” says ecologist Jan van Gils of the Royal Netherlands Institute for Sea Research in Texel,"
AKA - Send More Money.