The land of Old Faithful wasn’t always so lush. Two decades ago, Yellowstone National Park was the victim of defoliation, erosion and an unbalanced ecosystem. But in 1995, everything changed.
That was the year wolves were reintroduced to the park. Before then, government predator control programs had all but eliminated the gray wolf from America’s lower 48 states. Consequently, deer and elk populations increased substantially, resulting in overgrazing, particularly of willows and other vegetation important to soil and riverbank structure, leaving the landscape vulnerable to erosion. Without wolves, the entire ecosystem of the park suffered.
As a top predator, wolves are one of Yellowstone’s linchpins, holding together the delicate balance of predator and prey. Their removal in the early 20th century disrupted food webs and set off something called a “trophic cascade,” in which the wolves’ natural prey (in this case, elk) multiplied, all the while consuming increasing amounts of foliage. The phenomenon occurred again in reverse when the wolves were reintroduced and the natural balance was restored.
When wolves were brought back to the park, they not only killed elk, but also changed their prey’s behavior patterns. The herbivores started to avoid areas like valleys and gorges where they could be easily hunted by predators. As a result, those areas began to regenerate, and species such as birds, beavers, mice and bears returned. Plant life once again thrived along the riverbanks and erosion decreased significantly. The stabilization of the riverbanks actually made the rivers and streams change course. With the reintroduction of just a small population of wolves, the landscape of the whole park transformed.
Hopefully, you have enjoyed this rare glimpse into the wildlife of Yellowstone National Park. Now you can see why there are so many tourists come to Yellowstone. Not only to see the amazing scenery, geysers and beautiful waterfalls, but the wildlife is in abundance to enjoy.