Wolves do more for their forest environment than the average person might be aware of. They play a key role in keeping everything in order. When the wolf is removed, everything becomes chaos. This was what became clear in 1962, when the wolves in Yellowstone National Park were hunted into extinction.
The role of wolves in Yellowstone are vital to the well-being in the park and the animals who inhabit it. When they were killed off, the health of the park decreased significantly. With the wolves gone, the elk had no competition and their population grew out of control. Everything was effected down to the very last drop of water. The trees were fewer and there was less vegetation due to the elk being grouped in large numbers, not worrying about anything. They ate and ate until there was no food left for the other animals.
The streams grew significantly smaller because the elk would constantly hang out by the water. This affected many of the animals that rely on the streams to give them shelter and food. The streams are so small that even the fish tended to stray away from them. The beavers took a heavy hit from this as they rely on the rivers to give them everything they need. No longer with the amount of vegetation they need, their numbers started to decrease fairly quickly.
The beaver numbers grew so small that by the time the wolf was reintroduced to the park in 1995 there was only one beaver colony left in the entire park. The elk ate all the vegetation the smaller critters usually ate, and the decreasing foliage led to no hiding places. This helped the birds, but only for a short amount of time as the trees became smaller and their numbers were decreasing. The entire park was unhealthy and this is all because the wolves were hunted down to the last one.
The first wolf was reintroduced in 1995, and from there everything started to go uphill. The wolves almost immediately started hunting down the elk reducing their numbers significantly. The elk went back to their old habits and strayed away from the rivers and the smaller numbers let the foliage grow back again. The rivers were able to expand, and along with that, came the other little creatures and bird species that used to call Yellowstone home.
This event is what informed scientists about how important wolves and other apex (top) predators are to our environment. Without the wolves, elk and deer populations would be so out of control that they would ruin their own environment. This proves that in nature there is always a line of power, with the apex predators on the top and prey on the bottom, but when the top animal goes missing, the bottom animals spiral out of control destroying their own existence and habitat.
Scientists are still researching all the effects that a top predator has on its environment. One thing they do know from Yellowstone is, if the top dog is taken away then an unbalanced environment is created and it will ruin the other species almost permanently.