“In some cases, up to half of their diets are coming from humans. It might be garbage, or corn residue, or house cats and pets”

SOME OF NORTH America’s big predators—wolves, mountain lions, bobcats, and the like— are now getting nearly half their food from people. It’s a big shift away from eating foods found in nature and could put them in conflict with one another, or lead to more human-carnivore encounters on running trails or suburban backyards. A new study from researchers at the University of Wisconsin-Madison and the University of New Mexico used hair, fur, and bone samples to identify the diets of seven carnivore species across the Upper Midwest, from the outskirts of Albany, New York, to remote Minnesota forestland. The scientists used chemical tracers to show that the animals were relying on human food sources either directly, such as by raiding fields or trash bins, or indirectly by preying on smaller animals that do, such as mice, rabbits, or sometimes even pets.

“These species are eating human food,” says Philip Manlick, a postdoctoral fellow at the University of New Mexico and the lead author of the study, which was published on Monday in the Proceedings of the National Academy of Sciences. “In some cases, up to half of their diets are coming from humans. It might be garbage, or corn residue, or house cats and pets,” Manlick says. “This is bad news for carnivores, because people don’t want predators eating their pets—and, generally speaking, people don’t like carnivores in their backyard.” The complete list of these carnivores studied in the report includes foxes, coyotes, fishers, and martens. And not only are they coming into contact with people more frequently (you probably already saw this six-minute viral video of the Utah jogger chased by a mountain lion after he got too close to her cubs)....

A FRIEND WROTE to tell me about fake green olives. When you write a book about adulterated, contaminated, and fake foods, you get a long list of examples from everyday news in your inbox. I started a running tab of these messages, before quitting after it topped 100. The list ranged from ersatz spinach, calamari, whiskey, pomegranate juice, olive oil, and honey to bogus coffee, almond milk, parmesan cheese, wine, chocolate, cantaloupe, and cereal. I’d sometimes get notices of GMO-related controversies too, because people weren’t sure how to fit the genetically modified foods into a real/fake schema. I think they wanted me to say whether these would be OK to eat, but all I thought was: Who decides what counts as “genuine,” and what assumptions are they using?

I’ve since moved on from the list, bookmarking the Food and Drug Administration’s section on the Recalls.gov website, with its near-daily notices of contaminated or fraudulent foods. It got tiring. Rebecca Solnit once wrote that “none of us is pure, and purity is a dreary pursuit best left to the Puritans.” Yet the fight for pure food would seem to be never-ending. My catalog of food-identity angst was full of echoes from the past.

Two hundred years ago, Fredric Accum became the first chemist to tabulate a list of food grievances into a book.

A Treatise on Adulterations of Food, and Culinary Poisons (1820) called out “counterfeiting and adulterating tea, coffee, bread, beer, pepper, and other articles of diet.” Accum framed the problems in starkly moralistic terms: nefarious, mercenary, criminal, unprincipled, fraudulent, and evil. And that was just the preface. He drew his biblical epigraph, “There is death in the pot,” from Kings 4:40. His frightening cover graphic showed a hollow skull and intertwined snakes. This would be the tip of the spear: In the decades ahead, a new library emerged of anti-adulteration, pro-purity compilations. By the end of Accum’s century, grocery shelves had created a world so full of suspected fakes and frauds that consumers thought the problem was getting worse. By then it was the Gilded Age, after all, where a layer of thin gold disguised the true rot and corruption festering just below the surface.