Editor's Note: The following is an excerpt from Cristina Eisenberg's  book The Wolf’s Tooth.

A doe burst out of the forest and tore across the meadow, two wolves in close pursuit. This drama unfolded not twenty feet from where my young daughters and I knelt in our garden peacefully pulling weeds, our pant legs wet with morning dew. One black, the other gray, the black wolf in the lead, they closed in on the doe's haunches. In less than two heartbeats they pierced the deep wood on the far side of the meadow, leaving a wake of quaking vegetation.

We live at the base of a mountain in northwestern Montana. As wild as the wildest places in the lower forty-eight United States, it isn't quite paradise, although the handful of us who live here think it comes close. Midway up the mountains, overgrown clear-cuts show up as yellow-green rectangles against the darker green of old-growth forest. From our cabin you can walk due east beyond the state forest lands and not encounter much more than federally protected wilderness for a hundred miles.

Landscapes shape us and speak to us on a primal level. Most of us have a landscape we intuitively comprehend. This is mine. I open the front door of my cabin and find wolf tracks pressed into the snow. In spring, even before I see the grizzly lumber out of the forest to dig roots, I smell its ripe essence. These discoveries give me pleasure and an unspoken awareness of the natural order of things.

Humans also have a primal relationship with large predators. This relationship has been eloquently elucidated across the ages in Paleolithic petroglyphs of dire wolves and other creatures sharp of tooth and claw and in medieval paintings of wolves menacing sheep. Wolves began to recolonize our area in the early 1990s. Since then we had been hearing them howl from the shoulder of our mountain and occasionally finding their tracks. But we had never seen them— not until that misty August morning when they ran across our meadow. For some long moments after they passed we knelt motionless in the garden, at a loss for words. Then curiosity kicked in and we stepped outside our small fenced yard to follow the wolves' trail.

I marked one track, and from it we located others laid out in a gallop pattern. We even found the spot where one of the wolves had turned to look at us, a motion that had caused its left front foot to break forward. Fascinated, we continued to follow the subtleties of their trail—which sometimes consisted of little more than a few bent blades of grass that even as we watched were springing back upright. And I wondered how many other times wolves had run through our land and I'd missed the evidence.

In the fifteen years since wolves returned, the deer had been behaving differently—more wary, not standing in one place, eating all the shrubs down to nothing. After the first three years I seldom saw deer browsing in the meadow, and then only for brief periods. And after a decade the meadow was nearly gone, with shrubs and young aspens filling in what used to be open grass. Until we saw the wolves hunting, I had never actually observed a trophic cascade in action.

The Green World Hypothesis
In 1969 Loren Eiseley wrote an evocative story, "The Star Thrower," about a man who walked the strip of wet sand that marks the tide's ebb and flow, tossing sea stars that had washed ashore back into the ocean. Motivated by a need to save them from death, each day he returned the stars to the ocean. At one point in the narrative, Eiseley commented on the apparent futility of this task.

In the real world the star thrower is a scientist, and death is running even more fleet than he across every ecosystem on this earth. Like Eiseley's star thrower, Robert Paine is motivated by promoting life, although the results of his actions are far less futile and best described as utterly Eltonian. Considered the father of trophic cascades science, Paine has spent most of his life studying aquatic communities. I visited his University of Washington lab, which overflows with the products of a long and illustrious career: books and papers he's authored, photographs of the intertidal world he's studied for so many years. He sums up his work in two sentences: "You can change the nature of the world pretty simply. All you do is get rid of one species." As a young scientist he proceeded to do just that, experimentally removing sea stars in control plots, thereby creating profound changes in the intertidal community he studied.

3 Comments

1. 1. John_Toradze 07:02 PM 8/13/10

   Good article. I am reminded of the probable effect of humans on sea turtles in our earliest days, probably traveling the coasts of the world's oceans harvesting sea turtles and their eggs as a primary food source. As that resource was hunted to extinction, we had to evolve to deal with other food, and so it went. And I am reminded of the evidence in neanderthal ears that they were deep divers, foraging for shellfish like the Japanese Ama women.
   
   We are evolving now, and quite rapidly. We are forcing upon ourselves a coming cataclysm that will reverberate through the ages as some of us survive it, and others do not. So it goes.

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2. 2. Butterchicken10naan22 07:11 PM 8/17/10

   Predators are the quintessential thing that keeps ecosystems running the way they are. Eliminating predators, such as humans, would create an overpopulation of the prey - such as chickens, cows, hogs, and other animals - and would cause agriculture to grow limitlessly (forests could grow without deforestation, plants could grow without genetic breeding, flowers could grow with human manipulation).
   Predators do play an important role in our lives.

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3. 3. ssm1959 04:54 PM 8/19/10

   An unconsidered but related area is how herbivory patterns can open a habitat to invasion by non-native flora. Our experience in southern Wisconsin reveals that overpopulation of white-tailed deer radically affect the local flora tipping reproduction in favor of non-native, non-food source plants. Even modest steps to reduce the deer population has resulted in a significant increase in reestablishment of native species.

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