 In 1995, 14 wolves were reintroduced to Yellowstone National Park. From there, those 14 wolves basically saved the entire park's collapsing ecosystem. Let's talk about that. Don't forget to subscribe so you never miss an upload, and let's jump in. On March 1st, 1872, President Ulysses S. Grant signed the National Park Protection Act into law, creating the first National Park, Yellowstone. The goal of creating the National Park was to preserve the natural landscape and wildlife for generations to come. The creation of Yellowstone protected most of the native species, but it didn't provide protection for most of the predators, like the wolves. As a result, by 1926, all the northern Rocky Mountain wolf packs had been hunted to extinction. Although reports of single wolf sightings continued, they weren't enough to hold the wolf's prey at bay. By the mid-20th century, the deer and elk populations increased substantially, resulting in overgrazing, particularly of the willows and other vegetarian important to soil and riverbank structure, leading to heavy erosion. As a top predator, wolves were one of Yellowstone's lynchpins, holding together the delicate balance between predator and prey. The removal in the early 20th century disrupted food webs and set off something called a trophic cascade. The wolf's natural predators, in this case the elk, multiplied, all while consuming increasing amounts of foliage. This hurt the species that relied on that vegetation, like the birds who nested in the trees and the beavers who used the willows to create their dams. And without the beaver dams, hundreds of native fish species started to decline. And as the fish declined, so did the animals that fed on them, like the foxes and bears. By removing a single species, a cascade of negative effects propagated outward throughout the ecosystem. In 1974, the gray wolf was officially recognized as endangered, and so recovery efforts were mandated under the Endangered Species Act. The very next year, the long process to restore wolves to Yellowstone began. But for a long time, problems were evident. The program lacked both the necessary funding and any meaningful willpower to get it done. Despite the fact that, legally, restoration was supposed to begin in 1975, Congress only got around to appropriating funding in 1991, only about two decades late, which by today's standards might actually be a fast pace. After receiving more than 160,000 public comments, the most of any federal proposal at the time, 31 gray wolves were drugged and abducted, or relocated as conservationists like to call it. From Canada to Yellowstone. When wolves were brought back to the park, they finally killed the overabundance of elk. The elk populations decreased from more than 15,000 in the early 90s to about 6,000 last year. Not only did their numbers dwindle, but the wolves' mere presence was enough to change the elk's behavior. They started to avoid Yellowstone's valleys and gorges, where they could easily be hunted by the newly introduced wolves. As a result, those areas began to recover, and by 2006, some aspen trees had grown tall enough to where they were too big to be eaten by the elk. These growing trees provided a habitat that allowed for greater diversity and abundance of bird species, like yellowthroats, warbling veros, and song sparrows. They were finally able to nest again. And with the increase in wooded area, beavers were able to return. The number of beaver colonies in the park increased from 1 in 1996 to 12 in 2009, allowing for an explosive growth in fish wildlife. It might sound a little strange that beaver dams help fish populations, but by rising the water level and calming the stream, they make it easier for fish to hang out and reproduce. For reference, Wyoming streams with beaver ponds have about 75 times more abundant water life than those without. And without herbivores eating so much vegetation, plant life along the river banks once again thrived, and erosion decreased significantly. The stabilization of these river banks even made the rivers change course. With the reintroduction of just a small population of wolves, the landscape of the whole park was transformed. While these transformations have been undoubtedly beneficial at preserving Yellowstone's ecosystem for future generations, this might not be set to last. In 2018, Congress added a record number of anti-wolf measures to the appropriation bills that fund the Department of the Interior that governed the nation's parks. These measures were block protections in the Endangered Species Act from applying to a variety of wolf populations and would likely lead to them being hunted once again. In 2015, it was estimated that there were about 500 wolves in the greater Yellowstone ecosystem. That means that after only a few years of hunting, they could be brought back to extinction. That's one of the difficulties with conservation. It can take decades to save an ecosystem, but only a few years to destroy it. If we don't act fast, wolves could once again be subject to the same hostile extermination practices that push them to the brink of extinction. But hopefully, they'll be howling at the moon for years to come. I hope you enjoyed getting smarter with us today. If you did, be sure to subscribe so you never miss an upload. And remember, there's always more to learn.