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Utah Environment
6:00 pm
Fri February 21, 2014

Yellowstone Grizzly Bear Population Threatened By Beetle Resurgence

After years of work from the U.S. Fish and Wildlife Services to secure the future of the grizzly bear population in the greater Yellowstone area, the species is under consideration for removal from the endangered species list. However, some experts believe the change of status may be premature because of a great threat to the bears’ environment.

The grizzly bear population at Yellowstone National Park is being considered for removal from the endangered species list, but a threat to one of their food sources could hurt the species’ survival.
Credit U.S. Fish and Wildlife Services

The 22 million acres are experiencing a resurgence of the mountain pine beetle as a threat to one of the grizzly’s main food sources, the whitebark pine.


In 2009, it was found that over half the whitebark pine population of Yellowstone was highly impacted by a mountain pine beetle infestation, while 95% had at least some impact. Wally Macfarlane, a research associate of watershed sciences at Utah State University says that though the beetle population was killed off in late 2009 by a severe cold snap, the battle for the whitebark pine is not over yet.

"What we're finding is that they're actually still persisting and it looks like the outbreak is now coming back," said Macfarlane.

The seeds of the whitebark pine provide the grizzly bears with needed fatty nutrients before hibernation, which is especially important for the female bears.

"When there's a good cone crop available the likelihood of successful pregnancies and then the size of the litters is greater," said Macfarlane. "The health of the grizzly population is closely tied with the health of the whitebark pine."

Macfarlane says the seeds are not only nutritious, but are a safe food source for the grizzlies. With the infestation and lack of food, bears move down from the mountain areas resulting in more bears being removed from the area or being killed.

Macfarlane fears removing the grizzly bear from the endangered species list with the whitebark pine’s survival still in jeopardy could result in greater danger for the population.