Over the last three decades, Yellowstone National Park has undergone an ecological cascade. As elk numbers fell, aspen and willow trees thrived. This, in turn, allowed beaver numbers to increase, ...

When gray wolves returned to Yellowstone National Park, the public heard a simple story: predators came back, balance ...

Far from their unfair stereotype as the villains in a children's story, wolves are key to the survival of their ecosystems. In fact, their very influence is why they're known as a keystone species — ...

Yellowstone wolf watchers were gathered in awe on the morning of Oct. 6, ogling a pack of at least five black wolves roaming through the sagebrush near Lamar Valley. But the crowd soon saw something ...

Johnnie LeFaiver took her son to the Lamar Valley in Yellowstone National Park this summer, because the experience of watching wolves there 20 years ago seared into her memory and she wanted Micah to ...

A new study documents the complex interactions between cougars and gray wolves in Yellowstone National Park and finds their ...

View post: Hugh Hefner's Widow Makes Startling Claim About Playboy Founder's Scrapbooks A man was caught on video approaching and spraying at a Yellowstone wolf pack. Bystanders shouted warnings. Park ...

This winter saw the most wolves from Yellowstone National Park killed in about a century. That's because states neighboring the park changed hunting rules in an effort to reduce the animals' numbers.

A keystone in an arch's crown secures the other stones in place. Keystone species play the same role in many ecological communities by maintaining the structure and integrity of the community. The ...