“When we try to pick out anything by itself, we find it hitched to everything else in the Universe.” – John Muir
Do you remember the game Okami? It’s a beautiful title that puts you in control of Amaterasu, the Shinto goddess of the sun, who comes to earth in the guise of a white wolf. Throughout the game your job is to heal the world around you, giving life to plants and animals. It is, in essence, nature fixing itself. Okami was not necessarily created with the purpose of displaying the importance of biodiversity in ecosystems, but the wolf-like character affects her environment much like real wolves do in their natural world–so much so that they can actually change the geography of the earth underneath their feet. How is this possible? How can a single animal change a physical landscape? Ultimately, they change it through the fragility and natural balance of ecosystems.
We witness this by leaving nature alone in its wonder… a term coined “rewilding” by environmentalist George Monibot. In the case of wolves being a top predator, it’s because of a phenomenon called a Trophic Cascade–a pattern that follows the interruption of the flow of a food chain from top-to-bottom. In this case, top predators have the largest effect on the environment around them. When wolves were removed from Yellowstone National Park, the biodiversity of its 3,468 square miles dwindled. Small predators began to dominate, killing rodents and fish while leaving the elk population entirely free of population control outside of human hunting. As a result, the elk, too big in number to be supported, destroyed what was once lush vegetation. River banks became unstable. Trees couldn’t grow. As a result, the animals that relied on the vegetation of the park left in search of food or died of starvation.
In 1995, scientists reintroduced wolves to Yellowstone in order to study their behavior–and they received far more data than they could imagine. Data that was not just on based on wolves, but on the importance of predator and prey relationships–of how everything was and is connected. The wolves sprang quickly on the heavy elk populations, increasing their own numbers while selectively killing their prey. Interestingly enough the wolves only killed elk calves or elderly females, which made sense to the wolves because they were the easiest elk catch–however, they were also the elk that were least likely to reproduce. Hunting the elk not only reduced the population, but it also herded them away from important high-risk areas of vegetation growth, such as open valleys and river edges. This allowed Aspens and willows to grow and expand, which then attracted songs birds to nest in the area. Beavers were also attracted to the vegetation in the rivers and built dams and habitats for otters, ducks, and fish.
The wolves also killed coyotes, which made room for rodents to enter the equation–then the rodents, fish, and ducks attracted Bald Eagles, weasels, badgers, and even other raptors. And lastly, after a few years, the rivers themselves began to change their structure and activity–their banks calmed by the vegetation. The rivers slowed and stabilized because the plants around them prevented soil erosion. That action, in turn, created more pools which, in turn, created even more habitats for the animals. And the great thing? The elk population is just fine because of the wolves strategic hunting; even bears are doing better because of the variety of berries and other animals introduced. The situation in Yellowstone is eye-opening because it shows us how fragile and connected things are. A single species, just one, changed the geography of an area simply by existing in it. By removing and reintroducing a species, we bear witness to the direct correlation of cause and effect in ecosystem chains. It echoes the words of naturalist John Muir, who said, “When we try to pick out anything by itself, we find it hitched to everything else in the Universe.”