Wolf packs were absent from Yellowstone for 70 years. It completely changed the behavior of other animals. It removed fear from the system.
Survival for most animals means finding a balance between eating and watching for predators. Fear plays a vital role in keeping animals alive. But when you remove the top of the food chain, like wolves, the balance tilts to one side and upends the system.
Without wolves in Yellowstone, elk could eat without fear of predators. They could sit in one place and graze all day. More offspring also survived which did the same. Eventually, the number of elk grew beyond the capacity of the park. In other words, they ate and ate and ate until they ate at a faster rate than the trees and other vegetation could grow. After seven decades, they grazed the park clean of new saplings. That changed the landscape, forced other animals to change their habits (or leave for other habitats), and upended the ecosystem.
But that all changed in 1995. The reintroduction of wolves to the park forced the elk to change their behavior. They quickly learned they couldn’t sit around and eat all day. They had to move more often. They were more vigilant of predators. So they ate less and avoided higher-risk areas of the park. Things compounded from there. Continue Reading…