Steps away from the general public restrooms in Yosemite Village, a buzzy cease in Yosemite National Park’s iconic valley, sits a brown steel dumpster. Visitors attain as much as open the trash chute. Their peanut butter jars and apple cores tumble right into a sealed compartment. The slot slams shut. Then, they clip a tethered metal carabiner by way of a loop, which prevents much less dextrous creatures from getting entry. “USE CLIP,” reads a sticker on the chute. “SAVE A BEAR.”

“Bears have evolved to be these food-finding machines,” says Heather Johnson, a analysis wildlife biologist with the US Geological Survey Alaska Science Center and a member of the IUCN North American Bear Expert Team. Yet local weather change is making it tougher for them to discover a meal within the wild. Bears choose consuming their pure meals—grasses, berries, pine seeds, and acorns. But droughts, for instance, harm roots, shrivel berries on the vine, and power oaks to abort their acorns.

So bears have gotten more and more prone to scavenge from folks. They’re good at it. “I did my work in some of the wildest places in Colorado, about as far from roads as you could get,” Johnson continues. When pure meals was scarce, the bears she studied “would beeline 20 miles as the crow flies to go to where there’s human developments, foraging on people’s orchards and trailer parks for garbage.” When bears search out human meals, that places them at larger threat of battle with folks—one they’re prone to lose.

The United States is residence to roughly 300,000 notoriously omnivorous black bears; they’re the commonest and broadly distributed bear species in North America. (Yosemite has about 500 of them.) Black bears very not often assault folks; they’re usually much less aggressive towards folks than grizzlies. Outliers exist: A black bear killed a person unprovoked in Tucson, Arizona, in June. But these bears are extra typically those that get damage. Hunting for meals, they enterprise into site visitors or harm property, trigger a nuisance, and get euthanized. “That’s why we’ve seen this population decline when we have this big flood of bears really seeking out human foods,” Johnson says.

Hotter seasons are additionally amplifying encounters between people and wildlife, making run-ins extra frequent. In her earlier job with Colorado Parks and Wildlife, Johnson tracked the a number of forces driving human-bear conflicts, essentially the most well-studied being hibernation. Bears hibernate when chilly climate makes meals scarce. But hotter winters means bears begin hibernating later and emerge earlier.

“If they’re awake for more of the year, they have more time to get into conflicts with humans,” agrees Gloria Dickie, a journalist and the writer of Eight Bears, a ebook launched this July about every of the world’s eight remaining ursine species. “It’s basically just more opportunities to die.”

Those results compound when bears can entry human meals—be it trash from properties cozied as much as the wilderness or from snacks packed in by campers. These additional energy shorten their hibernation. (Bears that hibernate much less additionally seem to age faster.)