The police came at dawn. Karen Espersen watched them drive into the valley: more than 40 cruisers in a line. They were on a mission from the government. All of her ostriches must die.

Karen and her business partner, Dave Bilinski, were standing in the outdoor pens of their farm in the mountains of Canada’s West Kootenay. The fate of their flock had been taken up by right-wing media, and had become another front in a spiritual war. An angry group of their supporters, with signs and walkie-talkies, gathered on the property. They’d set up a barricade to slow the cops’ advance: several logs laid across the dirt near the turnoff from the highway.

The activists had been camping out for months; their numbers sometimes reached into the hundreds. They knew the government was saying that the ostriches had bird flu, but they were convinced that this was cover for some other, bigger scheme. The feds were conspiring with the United Nations and Big Pharma, they said. Small farmers’ rights were being trampled. But Dave and Karen’s birds had other, more powerful friends. Robert F. Kennedy Jr. was making calls to Canadian officials; Dr. Oz had offered to evacuate the ostriches to his ranch in Florida.

Canada “respects and has considered the input of United States officials,” the nation’s deputy chief veterinary officer had said. But rules were rules, and birds were birds—even if they were the size of refrigerators. And so a convoy of police had been sent to occupy the farm. Law-enforcement drones were flying overhead. The electricity was cut off.

The farm’s supporters had already threatened local businesses that were renting equipment to the cops, saying they would shoot employees. Then someone claimed that they’d placed a bomb somewhere on the property.

At 7 a.m., while the police were stuck behind the logs near the highway, a man slipped out of sight, donned a balaclava, and grabbed a jerrican of fuel. He crept over to the next-door neighbor’s house and doused its front with gasoline. Not more than 50 yards away, a group of ostrich activists stood around a bonfire, streaming from their phones as they sang “The Battle Hymn of the Republic.” When the neighbor came outside and tried to chase the would-be arsonist away, her screams for help were broadcast live on social media, above the sound of “Glory, glory, hallelujah.”

Alana Paterson for The Atlantic Karen’s home on the farm. Karen and her business partner, Dave Bilinski, have raised hundreds of ostriches for decades.

For decades, Karen and Dave had been raising hundreds of ostriches on a 58-acre plot in the small town of Edgewood, British Columbia. They’d earned a living from the meat and hide and feathers, and from a moisturizing lotion that they made from rendered ostrich fat. They’d also welcomed tourists to the property, bused in through the Monashee Mountains on a farm safari. But in mid-December of last year, the flock at Universal Ostrich Farms was overtaken by disease. The young birds in particular were having trouble breathing. Mucus leaked from eyes and beaks. Some were clearly feverish: They were roosting in puddles, even in the cold.

Over the next few weeks, the birds began to die, one by one, and then in groups. Dave hauled their carcasses across the property and buried them in 10-foot holes. The vet was out of town, so Karen did her best to nurse the sick. But more than 20 died, so many that they didn’t fit into the pits. Dave had to stash the rest beneath a tarp.

Locals noticed what was going on; you could see ravens feeding on the carnage from the highway. On December 28, someone notified the sick-bird hotline set up by the Canadian Food Inspection Agency, which monitors and manages agricultural diseases. Now the government was asking questions. Was there standing water on the property? Were the ostriches outdoors? Had Dave been aware of any wild birds nearby?

In fact there was some standing water, and the ostriches were never not outdoors, and lots of wild ducks had alighted in their pond and now were poking in the flock’s straw bedding and leaving droppings by the food bowls. To the CFIA, it sounded like a recipe for bird flu. A pair of government inspectors showed up two days later, in masks and Tyvek suits, and swabbed a couple of the carcasses. Their test results came back on New Year’s Eve: The birds were positive for the “H5” part of H5N1, the deadly strain of avian influenza that has raged through North America in recent years. According to the Canadian authorities, and in keeping with the nation’s agricultural-trade agreements, the outbreak had to be stamped out. The birds would have to die.

Alana Paterson for The Atlantic Ostriches at Universal Ostrich Farms

An ostrich is of course a grand and silly thing: more than six feet tall with giant eyes, a 350-pound sedan on muscled stilts. It chirps and booms and honks and grunts.