Yellowstone National Park elk herds, among the most studied wildlife populations in the world, provide a window into how climate change affects complex ecosystems. Rising temperatures are reshaping every aspect of their environment.
Changing Migration Patterns
Elk traditionally migrate between high-elevation summer ranges and lower winter ranges. Warmer winters now allow some elk to remain at higher elevations year-round, altering centuries-old migration patterns and their ecological effects.
Vegetation Shifts
Earlier spring green-up affects the timing of nutritious forage availability. Elk that time their calving and migration to historical vegetation patterns may find themselves out of sync with food resources—a phenomenon called trophic mismatch.
Predator Dynamics
Climate change affects the balance between elk and their predators. Snow depth influences wolf hunting success. Grizzly bear activity periods are extending. These shifts ripple through the entire Yellowstone food web.
Disease and Parasites
Warmer temperatures allow parasites and diseases to survive and spread more readily. Chronic wasting disease and other health threats may increase as climate conditions shift.
Ecosystem Implications
Elk influence vegetation, stream health, and countless other species. Changes to elk populations cascade through Yellowstone ecosystem, demonstrating how climate change affects even protected wilderness areas.