Wolves can Alter the Course of Rivers
If you think the idea of wolves altering the course of rivers and transforming an entire landscape sounds like the stuff of fantasy, then we urge you to watch this incredibly captivating four minute video.
While it’s true that wolves kill some animals to survive, they also give life to so many others.
When wolves were reintroduced to Yellowstone in the mid 1990’s, the impact they had on the environment was almost immediate, and absolutely positive. As a result of their reintroduction, the entire ecosystem of the park changed and came alive in ways that nobody anticipated.
In the absence of wolves, the deer and elk population had grown unchecked, and despite human efforts to control them, they had managed to strip too much of the park of it’s vegetation. They had grazed it away.
Yet as soon as the wolves arrived, even in their initial small numbers, they started to have remarkable effects. Yes, of course, they killed some of the deer. But that was expected, and alone didn’t change anything dramatically. What was not fully anticipated was the impact the wolves had on the behavior of the deer herds. Although these deer had not known wolves for many generates, they knew exactly what to do. They began entirely avoiding parts of the park where they would be easy prey, such as the valleys, the gorges, and the open plains. And immediately, these places began to come alive. Grass, flowers, bushes and trees, long absent and stripped bare by hunger deer, began to regenerate. Places that had been mostly dirt and rock, within only five or six years, became lush, green, and forested as the Aspen and Willows grew quickly.
When the trees came back, so did the birds. The number of song birds and migratory birds rebounded and increased remarkably. And when the trees came back, so did the beavers who like to eat the trees, and to turn them into damns. And the newly created beaver ponds provided habitat for muskrats, otters, ducks, fish, reptiles and amphibians.
The wolves also killed coyotes, which like the deer, had reproduced for too long with no natural checks on their population. And as a result, the number of rabbits and mice grew also, which meant more hawks, more weasels, more foxes, more badgers. Ravens and eagles came and feasted on the remains of wolf kills. Bears also fed on them, and their numbers began to rise as well, partly because of the increased amount of berries growing on the newly reborn shrubs.
And while all of this is fascinating by itself, here’s where it starts to become truly amazing. The wolves changed the behavior of the rivers. With all the new vegetation, there was less soil erosion, and the rivers began to meander less, their banks stabilized, tightened, and collapsed less often, creating deeper rivers and stable pools, all of which created new habitats and homes for more wildlife. The wolves literally changed the rivers.
While small in number, these wolves not only rebalanced the ecosystem of Yellowstone, but also transformed it’s physical geography, making it more rich, alive and beautiful.