Wolves as apex predators influence entire ecosystems through trophic cascades, with their presence or absence affecting the welfare of prey species and ecosystem health.
Wolf welfare intersects with ecosystem-level welfare through the trophic cascades that apex predators generate. The Yellowstone reintroduction revealed that wolf presence changed elk behavior — elk avoided riverbanks where wolf ambush was possible, allowing riparian vegetation recovery, which in turn supported beaver, songbirds, and fish. This demonstrates that predator welfare and prey welfare are not simply in opposition: ecosystems with functioning apex predator guilds produce conditions where prey populations are more behaviorally diverse, physically healthier, and better adapted to their environment than in predator-free systems. The individual welfare of prey animals killed by wolves remains a genuine ethical question, but the population-level and ecosystem-level evidence suggests that wolf presence creates conditions associated with higher overall welfare across the prey population.