Does Whitebark Pine Decline = Increased Grizzly Attacks?

3 grizzlies

Grizzly family walks

Grizzly bears don’t really need whitebark pine seeds, the Interagency Grizzly Bear Committee reported this week.  Oddly, the bear group says they needed to issue the report not because of a recent New York Times editorial, not because of the mauling death of a camper just outside Yellowstone on July 28, the second this year after none for 25 years.

Neither the editorial nor the report mention that the federal government is about to decide whether whitebark pine should be given endangered species protection, though that seems to be the big issue.  The tree, already assaulted by an invasive fungus, has a new threat from a foreign beetle. Cold temperatures used to keep the beetle at bay, but global warming changed that.

The July 26 editorial is teeny, and in only one of five wee paragraphs does it mention grizzlies:

The worst damage will be done to grizzly bears, which feed heavily on pine nuts before hibernation. Studies have shown that in good pine-nut years, grizzlies stay in the high country where white bark pines prevail. In bad years, the bears are driven down to lower elevations where they interact more frequently — and tragically — with humans.

Even more curiously, the August 3 committee report mainly just takes on a strawman claim that whitebark pine decline=grizzly decline. That’s not what the Times said. The task force doesn’t refute the real claim, whitebark pine decline=grizzly conflict increase. It just says it’s not the biggest factor.

Although conflicts between grizzlies and humans are higher in autumn in poor whitebark seed years, all models of bear/human conflicts showed that the number of conflicts in any given year is best predicted by the number of bears in the population not whitebark pine seed production.

report from the Natural Resources Defense Council, which was mentioned in the editorial and which argues for endangered species protection, goes even further than that Times and says of grizzlies:

During years when pine seeds are scarce, conflicts with humans escalate dramatically, as does the death rate among bears. (Blanchard 1990, Mattson et al. 1992, Blanchard and Knight 1995, Schwartz et al. 2006).

Late summer and fall is the season when they eat the pine seeds. These bears were hungry and skinny. Bear attacks are generally divided into two categories: bears are either defending themselves (or young or food) or they’re trying to eat someone. The predatory type is rare, but that’s what this was.

The bears first attacked and partially ate father and fisherman Kevin Kammer, 48, of Grand Rapids, MI. The bears, or at least the mother, went to other tents. She started chewing on the arm of  Deb Freele, 58, of London, Ontario, until Freele played dead. “‘I want to live.’ And I just told myself, ‘Play dead.’ … As soon as I went limp, I [could] feel his jaws get loose and then he let me go and he went away,” she told the Early Show. Normally playing dead only works with a defensive attack; the bear stops when it no longer thinks you’re a threat.

In this case I have to think that the 225-pound mother bear was trying to get food for her three cubs. The fact that she was caring for three cubs is probably another factor. Twins are typical.  Triplets aren’t unheard of, but they would certainly put a huge strain on a mother. Cubs can graze at this age, but the cow provides milk and meat. Grizzly cubs are weaned between July and September. Until then, they cry for milk. You can see mothers all over the animal kingdom getting worn down by their adolescents’ demands this time of year.

The cubs were all captured and taken to ZooMontana in Billings, where Zoo executive director Jackie Worstell said they were malnourished, weighing 60 – 70 pounds, instead of the normal 80 -130 pounds. “It may be an indication of what happened,” Worstell told the AP. “There’s obvious signs of stress and malnourishment. Maybe (the sow) was desperate.”

Both maulings this summer were tragic as well as inexplicable. The 425 pound bear that attacked retired teacher Erwin Evert, of Park Ridge, IL, wasn’t trying to eat him. That bear was was in reasonable health, just not fat. Researchers commented:  “Resistance was low as well as percent body fat. bear was not thin or skinny.”

We’re never going to know if the grizzly mother and three cubs that attacked campers at Soda Butte on July 26 wouldn’t have been there if they had more pine nuts on higher ground.

Where to Go to See Bear

Where to See Animals Out West

Related posts:


On the advice of a right whale, we have closed comments for this post. If you have something really important to say, email us and we'd be delighted to reopen it for you. (The whale is only trying to prevent spam comments.)