Coming soon to you: bears -TGN

Steps away from the public restrooms in Yosemite Village, a bustling stop in Yosemite National Park’s iconic valley, are on a brown metal dumpster. Visitors reach up to open the garbage chute. Their peanut butter jars and apple cores tumble into a sealed compartment. The slot closes. They then clip a tethered steel carabiner through a loop, preventing less agile creatures from gaining access. “USE CLIP” is written on a sticker on the parachute. “SAVE A BEAR.”

“Bears have evolved into these food search engines,” said Heather Johnson, a wildlife research biologist at the U.S. Geological Survey Alaska Science Center and a member of the IUCN North American Bear Expert Team. Still, climate change is making it harder for them to find a meal in the wild. Bears prefer to eat their natural food: grasses, berries, pine nuts and acorns. But drought, for example, damages roots, shrivels berries on the vine, and forces oaks to break off their acorns.

So bears are increasingly likely to feed on humans. They are Good At the. “I did my job in some of the wildest places in Colorado, as far from the roads as possible,” Johnson continues. When natural food was scarce, the bears she studied would “fly 20 miles as the crow flies to go where there are human developments, foraging in orchards and trailer parks for waste.” When bears forage for human food, they are at greater risk of conflict with humans – one they are likely to lose.

The United States is home to about 300,000 infamous omnivorous black bears; they are the most common and widespread bear species in North America. (Yosemite has about 500.) Black bears rarely attack humans; they are generally less aggressive towards humans than grizzly bears. There are outliers: a black bear killed a man unprovoked in Tucson in June. But they are more often the ones who get hurt. They hunt for food, venture into traffic or damage property, cause a nuisance and are euthanized. “That’s why we’ve seen this population decline while we have a large flow of bears that are really looking for human food,” Johnson says.

Photo: Max Levy

Photo: Max Levy

The warmer seasons also mean more encounters between humans and animals, making run-ins more common. In her previous job at Colorado Parks and Wildlife, Johnson tracked the various forces driving human-bear conflict, the most studied of which is hibernation. Bears hibernate when the cold weather makes food scarce. But warmer winters mean bears hibernate later and emerge earlier.

“If they’re awake for more of the year, they have more time to get into conflict with people,” agrees Gloria Dickie, journalist and author of Eight bears, a book released in July on each of the world’s eight surviving ursine species. “It’s really just more chances to die.”

Those effects are magnified when bears have access to human food, whether it be waste from cozy homes in the wilderness or from snacks packed by campers. These extra calories shorten their hibernation. (Bears that hibernate less appear to do the same age faster.)