When in 1995 fourteen wolves were released into the wild in Yellowstone National Park, scientists did not suspect that this would radically change the entire ecosystem of the park.
There were no wolves in the park for 70 years, and all this time deer reigned there, which over the years of uncontrolled reproduction (all the efforts of people to control their population did not bring success) caused severe damage to the local flora. Fourteen wolves, of course, could not eat all the deer, but they forced those to be more careful in choosing places for grazing and to avoid certain parts of the park. In those places, vegetation began to revive. In six years, the number of trees has increased fivefold. Beavers have appeared, which need trees to build dams. Muskrats, ducks and fish have been bred in the backwaters. Wolves reduced the population of jackals, which led to an increase in the number of hares and mice, and they attracted hawks, ferrets and foxes to the park. The bears came to the park because they were able to drive the wolves away from their prey or eat up their scraps. The number of berries has increased in the park.
But the most amazing thing is that the wolves changed the flow of rivers. Their channels straightened and stabilized, and coastal erosion decreased. This happened because the influence of wolves on deer led to an explosive growth of trees and grass along the banks of the rivers, which led to their strengthening. The very geography of the park has changed, and all thanks to the fourteen wolves released there less than twenty years ago.