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Biology

Predator-Prey Dynamics of Wolves and Elk in Yellowstone

Quick fact

After wolves were reintroduced to Yellowstone in 1995, elk populations not only decreased but also changed their behavior—avoiding high-risk foraging areas. This allowed overgrazed willow and aspen stands to recover, which in turn stabilized riverbanks and boosted biodiversity, a dramatic example of a trophic cascade.

Why this is interesting

In 1995, wolves returned to Yellowstone after a 70-year absence. Their reintroduction didn't just change the wolves' lives—it transformed the entire park, even the rivers. How could one predator reshape an entire ecosystem?