Yellowstone’s Grizzlies are More Dangerous Than Glacier’s

Yellowstone has seen a nearly 50 percent increase in conflict between bears and humans in the past five years: A new report by the U.S. Fish and Wildlife Service comparing Yellowstone with Glacier shows that in 2011 there were 17 people charged by grizzlies in Glacier, while in Yellowstone 62 were charged — nearly four times more. This despite the fact that Glacier’s bear population is far greater, 1,000 bears vs. Yellowstone’s 600.

But even with all those interactions there were just two deaths by grizzly last year in Yellowstone, and throughout the national parks 81 percent of all bear charges resulted in zero injury. Still, the study, along with another one by the USGS, yields a lot of valuable information about why Yellowstone’s bears are more dangerous, and it comes back to a changing animal habitat that’s forcing bears to interact more with people.

For one thing, pine trees in Yellowstone are more endangered than the bears, with white bark pines falling prey to blister rust. That takes away an important part of the bears’ usual diet, pine nuts. And cutthroat trout have also disappeared because of the introduction of predatory lake trout — which can’t be caught by bears because they spawn in waters too deep for bears to fish. What’s left to eat is game…and human garbage.

Which accounts for why the bulk of a grizzly’s diet in Yellowstone is meat, while in Glacier it’s nearly 97 percent vegetarian.

Beyond the dietary constraints on bears in Yellowstone, the conditions of bear-on-people interactions are different as well. In Yellowstone, bears are more habituated to people, which isn’t a good thing, and the USFWS study, going back to 1990, shows that in 38 percent of bear charges human food was present, suggesting that people are too often careless with both their food and their trash.

Further, in the bulk of charges people weren’t carrying pepper spray. And unfortunately in too many instances of fatal attacks the victims ran away from the bears rather than standing their ground, making noise, etc., to scare the bears. Lastly, the most likely victims of charges were lone hikers or lone hunters, suggesting that there really is safety in numbers.

Environmental coverage made possible in part by support from Patagonia. For information on Patagonia and its environmental efforts, visit www.patagonia.com. Grizzly photo by Shutterstock

{ 8 comments…read them below or write one }

  • evan

    Way more visitors to Yellowstone, and I’d venture to say those visitors are typically more clueless of how to avoid negative bear encounters than those who venture into Glacier.

  • eb

    They need to control for number of visitors, park size, and attacks per human-bear encounter. Sure, there are more human-bear incidents in Yellowstone, but let’s phrase the conclusions properly. Are the bears more dangerous in Yellowstone or just having more human interaction leading to more incidents?

  • Dan Murphy

    Clueless visitors in Yellowstone is right. While visiting there two years ago, we came upon a griz just before sunset, along with a number of other people. While we just hung out and watched the bear, people inched closer and closer, then chased after the bear when he took off. Jeez, people.

    BTW, this is my newest favorite website – not sure what took me so long. No surprise Casimiro and Frank are involved. Thanks, guys.

  • Dave

    Come on, pine nuts and cutthroat!!??? give me a break!…. Pine nuts should have been replaced by an ample berry crop after the Yellowsotne fire….Lake trout replacing cutthroat would effect the stream coming of Yellowstone lake. It has to do with stupid people, getting too close and not respecting the danger until too late. Of course there is no mention of the drastcially reduced elk populations by wolves… A lot less winter kill available and far fewer calves to feed on! Now I repsect your credibility! Not!

  • Roger Hewitt

    Conclusions about Yellowstone Bears being more aggressive is highly doubtful. The count of human-bear encounters is credible. But grizzlies are likely grizzlies with different terrains in Glacier and Yellowstone, more encounters in more open terrain versus Glacier’s narrow trails and more mountainous terrain, and more habituation in Yellowstone; not inherently more aggressive because the Yellowstone bears are more meat eat eaters versus more (97%) vegetarian Glacier. Just dumb conclusions implying inherently more aggressive Yellowstone bears because they eat meat. What does that make Glacier bears: Tree hugging, tourist buddies just hanging out, vegetarian grizzlies?!

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