You can read a hundred articles about wolves and their prey, including the ODFW Wolf webpages, but not a single one will explain exactly WHY wolves are, or were, on endangered species lists.
If you look hard enough you really can find hundreds of articles on the WHY, but here is an interesting one that sums up the complexity of the issue:
Scientific American: “Can Wolves Bring Back Wilderness? [Excerpt]: People may find it hard to adapt to an ecology of predation and fear,” by Jason Mark on October 9, 2015:
Here are a few excerpts from the larger Scientific American excerpt:
“… Our conflicting emotions about the wolf, it appears to me, have more to do with our species’ similarities than with any differences. We’re more like wolves—with their big appetites and their guile—than we are like the naïf-ish deer. Read a bit of canis lupus biology, and after a while the wolf tales begin to sound Shakespearean—a tumult of rapaciousness, generosity, fratricide, outcasts and loners, loyalty and affection….
Later, after years of studying how ecosystems work, Leopold would recognize what a mistake it had been. Without wolves, the deer population exploded, the deer began to eat too much, and the woodlands started to suffer. In his short essay, “Thinking Like a Mountain,” Leopold wrote that a landscape without wolves “looks as if someone had given God a new pruning shears, and forbidden Him all other exercise. . . . I now suspect that just as a deer herd lives in mortal fear of its wolves, so does a mountain live in mortal fear of its deer….
Contrary to all the myths and legends he had grown up with, Leopold concluded that predators also have a place in nature’s design. Yet he knew that such a truth would be hard for many to hear: “Only a mountain has lived long enough to listen objectively to the howl of a wolf.”
Apex predators influence the behavior of their prey, and that new prey behavior in turn affects the species on a lower trophic level. The mere presence of a top carnivore ripples through the landscape.
Imagine: a wolf appears on the scene. Suddenly, the elk can no longer loaf around the valley bottoms. They actually have to start paying attention to their surroundings and looking for threats. As the elk become more cautious, they begin to browse differently. Trees and shrubs are offered a reprieve. Aspens, once chewed to the ground, reappear along the riverbanks. The more robust greenery offers new space for other critters. Beavers come back. Mesocarnivores like coyotes begin to behave more cautiously. Cause-and-affect spills from one level of the food web to another, like a waterfall. The mark of the wolf ’s tooth, biologist Cristina Eisenberg says, is powerful enough to shape the course of a river….” [Link to Scientific American article: “Excerpted from Satellites in the High Country: Searching for the Wild in the Age of Man, by Jason Mark. Island Press. Copyright © 2015″