Wolves are only part of what affects Yellowstone’s elk and vegetation; other predators, weather, and human influences also play a role. When a nature documentary explains several causes, what helps you follow along: a diagram of the connections, a step-by-step story, or something else? Source: [NPS: Yellowstone wolf restoration](https://www.nps.gov/yell/learn/nature/wolf.htm) Photo: [NPS / Jim Peaco](https://www.nps.gov/features/yell/slidefile/mammals/wolf/Page-4.htm) · [Public domain](https://www.nps.gov/features/yell/slidefile/index.htm)