Yellowstone National Park, Wyo. » One of the most studied, photographed and filmed wolf packs in Yellowstone National Park appears to have reached the end of the trail.

Officials estimate more than 100,000 people saw the Druid Peak pack during its 14-year-run in the northeast corner of the park.

The pack numbered 11 wolves two months ago, but officials say the alpha female and other members were killed by other packs, the alpha male wandered off, and a skin infection called mange killed others.

"They're down to one and that one probably won't make it through the winter," said Doug Smith, Yellowstone's wolf biologist.

Other wolves have already moved into the Druid's old territory in the Lamar Valley, including the newly named Silver pack of four wolves.

"It's an example of there's never a vacant niche very long in nature," said Rick McIntyre, a Yellowstone Wolf Project technician. "It fills quickly."

The Druids provided groundbreaking insights to researchers on wolf interaction during their dominance in the park, partly because they didn't mind being viewed from roads.

Researchers said that, in 2000, an alliance of three subordinate females in the pack are believed to have killed the pack's alpha female in what was the first intra-pack kill documented in the park.

Also that year, the Druids were one of two packs first documented killing a grizzly bear cub in Yellowstone.

At its peak in 2001, the Druids had 37 members. But the pack broke up and three new packs were created while other individuals traveled from pack to pack.

In 2002, a male member was caught in a coyote trap in Mason, Utah, 220 miles away. After being released it returned to Yellowstone and joined the Druids.

Another insight into wolf behavior came in 2003 when researchers saw the Druids perform a six-hour-long ritual song and dance that culminated with a new wolf joining the pack as the breeding male. The behavior had never been recorded in the wild before.

The pack seemed close to being wiped out in 2005 when it was down to four members and forced to the edges of its home range, but the next year surged back to reclaim much of its territory.

"It's quite a story," said McIntyre, who is not ready to count out the Druids. "I would say they are down and out, but not done yet."