Previous research on the effect of wolves on the food web has been criticized, raising questions about the predator’s role in the Yellowstone ecosystem.

Scientists debunk decades-long study claiming wolves' reintroduction triggered a dramatic transformation in Yellowstone.

In Yellowstone National Park — where gray wolves were reintroduced starting in 1995 — researchers have gone back and forth on whether the restoration of wolves has impacted the ecosystem. The idea is ...

A grey wolf prowls through Yellowstone National Park near Mammoth Hot Springs in Montana. A group of 66 wolves was reintroduced to Idaho and Yellowstone in the late 1990s. They now total 2,800 ...

Across North America, mountain lions, bears and gray wolves have made a remarkable comeback over the last 50 years. Once nearly exterminated, these animals have been recovering their populations and ...