The Ecology of Fear

If you want to maximize your deer population, include grazing as one of your mangement tools.

Researchers in Oregon have concluded, after extensive research, that prey species have a fear of predators and that prey species move away from their mortal enemies in an effort to survive. They have also concluded that this natural system has an important relationship to the success of other plant and animal life.

Impressive conclusion?

Interesting how a bit of research can lead to statements by politicians who are too eager to use science as a basis for social sculpturing. In our local paper (on a front-page feature article no less) Tri-Valley Herald reporter Suzanne Bohan uses the research to support her own conclusions.

” YOSEMITE NATIONAL PARK – More fear of fangs is what’s needed to revive hoof-worn Western lands.”

What’s wrong with this? From what I see, the research related to this subject is most applied to wolves. There are and have never been wolves in Yosemite.

Bohan then goes on to apply the “Fear” theory to mountain lions. Then she concludes that we don’t have enough of them and we need more lions in the park for the benefit of botanical success.

Horse poop. Mountain lions are at equilibrium in California. Our habitat cannot support any more mountain lions. If you want to save the flora and fauna of Yosemite Valley, remove the tourists. They are what keeps the mountain lions away. Lions don’t like people.

Lions do move deer around and it is a benefit for the ecosystem. Human hunters do the same thing. After removing the tourists, we can then insert human hunters to assist the lions. The result will be a much improved Yosemite.

I’m all for it.

6 thoughts on “The Ecology of Fear

  1. So as I understand – we need more predators to get the animals to fear them? Riiiiigggghhhhht. That makes sense. More proof that stupidity knows no bounds. I would place a large bet that if a cougar screamed near a deer than had never seen, heard, smelled, or thought about a cougar in its life, that deer would still get the heck away from that area.

    I do like your problem solving, though. I think the same tactic would work for wolves in Idaho – remove the development of public lands and and insert hunters who are more than eager to help assist in keeping wolf populations under control.

  2. This report has been causing some definite heartburn around these parts…

    I realize the report itself was written to argue a theory, and not as an end-all explanation for anything, but as you pointed out, it’s being co-opted to make an argument that’s as flawed as saying guns cause crime.

    The basic premise is that the eco-system is a balance, and unsettling that balance causes a domino effect of impacts and changes… in this case, the absence of predators lets the large herbivores overpopulation, in turn overeating in the habitat and changing the nature of the plants in the habitat.

    It makes sense, except that the report also makes it sound like the absence of predators is a sole cause, while no one mentions things like fire suppression, the flooding of the Hetch-Hetchy Valley, and the drainage of other marshy areas… plus the influx of tourists and development.

    Yeah, humans wiped out the grizzlies, but the lions are thriving and pretty much always have been. There’s no shortage of predators out there, in Yosemite or anywhere else in this state.

  3. I’m the writer of the article, The Ecology of Fear, and I’d like to respond to your comments:

    1) The opening paragraphs state:
    “YOSEMITE NATIONAL PARK — More fear of fangs is what’s needed to revive hoof-worn Western lands.

    That’s the view of pioneering scientists certain that a scarcity of cougars and other large predators is devastating large stands of oak, aspen, cottonwood and even spectacular wildflower blooms in Western wild lands because deer and other foraging animals no longer fear predators and are overgrazing as a result.

    “It’s one of the most exciting new ideas in ecology within the last 25 years,” said David Graber, chief scientist of the Pacific West Region for the National Park Service. “The whole notion of how important large predators are on the landscape is extraordinary.”

    That’s certainly not my conclusion, as the article emphasizes.

    2) Regarding your comment:
    “From what I see, the research related to this subject is most applied to wolves. There are and have never been wolves in Yosemite.

    Bohan then goes on to apply the “Fear” theory to mountain lions. Then she concludes that we don’t have enough of them and we need more lions in the park for the benefit of botanical success.”

    I expressly state that this applied to all large predators, and describe the wolf studies in detail. I point out that this finding only relates to Yosemite Valley, and that cougar populations are intact in the rest of the park, and I write:
    “No one is suggesting that cougars be reintroduced into Yosemite Valley, nor do they need it. Despite early 20th century efforts to eradicate cougars in the state, the agile, versatile and fecund cats have rebounded in the park’s backcountry.”

    I could go on, in challenging your characterization of the story, but I suggest that anyone reading this blog read the story itself carefully, as the author of this blog apparently failed to do.

    Suzanne Bohan

  4. Suzanne: I too suggest they read the story. If you’re not interested in promoting predation in Yosemite Valley, then I’m not sure what the point is. Is it only academic?

    Seldom does research make the front page unless it has some direct application.

    I don’t argue that predators play a significant role in helping maintain a delicate ecological balance.

    Ecological balance cannot be maintained in a park that hosts thousands of visitors to a relatively small area each year. One problem in Yosemite may be a lack of predation, but the overriding problem is too many people.

    I think most readers will be mislead by the article.

  5. If you want something to do take a look at the wolves in Lamar valley which is located in yellowstone national park The results to the rest of the ecology is clear but I will allow you to make your own judgement of reserch. You might look at the numbers of coyotes in the valley since 1994 and cross check with weasels and such. Oh and isle royale is great place to look up info about a closed population and the results that just one animla in chain can have.

  6. THe Lamar Valley coyote/wolf study is very interesting.

    I wonder if the Yosemite coyotes have filled the mountain lion nitch?

    The issue in Yosemite is not really whether the absence of mountain lions is causing damage to the habitat. There’s nothing we can do to make more lions for Yosemite, short of closing the park to people.

    There is a deer season for the D6 zone just outside the park and an increase in deer tags might reduce the deer population somewhat.

    I’ve tested the ecology of fear at home. My cats have eliminated the ground squirrels from my back yard and my garden is loving it.

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