Not so fast.....................................

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Posted by Ballpark Frank ( on 12:27:31 06/29/13

In Reply to: food study this fall posted by Hoot


The piece I read on the IGBST web site, says that "whitebark pine seeds are arguably the most important fattening food available to grizzly bears during late summer and fall". They speak of the conflicts that develop between bears and humans in poor seed crop years, when the bears don't have the "magnet" of whitebark pine nuts to keep them at high elevations. This is all true.

Now, here's the "rest of the story". In conversations with numerous grizzly subject matter experts, I have consistently been told that on average, only one in five years produces a robust, reliable whitebark pine nut crop. How can you base decisions on delisting on a food source that is only a substantial factor in 20% of your years?

There are other food sources that are also of significant importance, like spring beauties, cutthroat trout, winter-killed carcasses, army cutworm moths, army cutworm moth larvae, rut and road-killed bison in August, but they occur primarily at other times of the year, and shortages are less likely to result in bear/human conflict. This is as good a place as any to mention, for the benefit of others that read this thread, that there is a very important process that relies on female grizzlies entering their dens with substantial stores of fat. Female grizzlies mate in June, but a blastocyst is formed, which is free-floating in the uterus. It only implants in the uterine wall and develops into one or more bear cubs after the mom to be dens up in mid to late fall, AND has sufficient stores of fat to support the birth of cubs in mid-winter, and the nursing of same until emergence in April or May. This is a key factor in grizzly demographics.

The theory is that when the whitebark pine nut crop is poor (4 of 5 years statistically), bears migrate into areas of human habitation, where they are killed by hunters, management actions, and vehicles. There is some truth to this, however, I think the argument is over-exploited by those who find it convenient to support their campaign against de-listing. Most of the grizzlies killed outside the parks are adult males, although female grizzlies have taken hits just north of Yellowstone, mostly via conflicts with hunters in the fall. Male grizzlies make up the vast majority of bears killed in management actions due to attacks on humans, conflicts with hunters south of Yellowstone, and vehicular incidents. I believe we need more research on gender differences, by geography, in human-caused grizzly mortality outside the national parks in Greater Yellowstone. There are some conundrums, like, why is it that males, who are so territorial, go wandering outside their territories (acknowledging the obvious attribution due to food shortage), while females, who are less territorial, and have much smaller territories, are more likely to stay put. I think female grizzlies start becoming den-centric in the fall, staying in a steadily-shrinking concentric ring around their den site as fall progresses. (This is not original thinking. The Craigheads observed this behavior back in the 1960s, in the Hayden Valley area.)

We have heard plenty about griz-hunter conflict along the south boundary of Yellowstone, where some grizzlies have learned to associate the sound of a rifle report with a bounty of food. In recent years, we have had quite a few griz-man conflicts in the hills between the north boundary of Yellowstone and the Yellowstone River, virtually all involving hunters. Given what we know about the relative infrequency of good whitebark pine nut years, I am compelled to attribute this steadily increasing phenomenon more to a healthy grizzly population spreading out, than to the demise of whitebark pines.

There are a host of potential methods for dealing with the bear/hunter conflict near the boundaries, including hunting, banning hunting, and more intensive education/permitting of hunters in those areas. I'm not going there at this point. I've spent hours jawing with folks about that subject, and until grizzlies are delisted, I think we will see the status quo.

Here's a good one you never hear the scientists or the partisans in the delisting debate ever mention. We have found, via observation, that grizzlies actually feed on army cutworm moths TWICE each year. There is the one everybody seems to acknowledge, when the moths are all over the rocks up high, mating and laying eggs. We have observed grizzlies at the same high elevation IN THE FALL working the same rocky areas. They appear to be pigging out on army cutworm moth larvae. This is high calorie food, and we have observed female grizzlies with cubs taking advantage of it in close proximity to male grizzlies. That is a rarity, and typically only observed in places of great abundance, like the salmon runs in Alaska.

I tend to view much of the psychodrama that has been playing out as "amateur night", but I see both sides guilty of naivete and Pollyanic notions!


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