JACKSON, Wyo. - Increasing numbers of human-caused deaths and declining food sources have left, at best, an uncertain future for grizzly bears in the Yellowstone area, researchers from around the world were told.
Nineteen grizzlies were killed by people last year, the most since the bear was listed as threatened under the Endangered Species Act, said Louisa Willcox, a Sierra Club staffer from Bozeman, who has dedicated the last 20 years to grizzly conservation.
"Bears are still dying unnecessarily from human causes," she said last week during a meeting of the International Bear Association, which drew 400 participants.
Encounters with humans are increasing because of growing forest-edge subdivisions, poor sanitation that draws bears to developments, conflicts with hunters and surprise clashes in the backcountry, she said.
"Enough habitat is not protected and it's vulnerable under this administration," Willcox said.
The grizzly, with its low reproductive rate and requirement for large open spaces, could be "the hardest animal to save," she said.
Energy development being pushed around Yellowstone would be a disaster for bears by bringing roads, housing and fragmentation of habitat, she said. Bears and development "simply don't mix," she said.
Dwindling food sources are also a threat, biologist Dave Mattson told meeting participants.
Grizzly bears mainly dine on dead animals, whitebark pine nuts, fish and moths, he said.
Whitebark pine is under attack by a blister rust infection.
"The prognosis is for the inevitable spread of this disease," said Mattson, a former Yellowstone National Park researcher.
Moths, which travel up to 500 miles from the Great Plains, can be affected by agricultural practices far from Yellowstone or by global warming, he said.
Cutthroat trout are threatened by nonnative lake trout in Yellowstone Lake.
"The prognosis for grizzlies is at best, highly uncertain," Mattson said. "At worst it's grim."