Recently, Mary and I had the good fortune to watch and video the Mollie's-16 wolves strong-as they sorted and sifted a bison herd. This fascinating pack once called the Lamar Valley home. The pack-one of the first released into Yellowstone in 1995-was then called the Crystal Creek pack. While they denned in the Lamar Valley in April of 1996, the just released Druid Peak wolves attacked and killed the Crystal Creek's alpha male and all the pups. The two surviving Crystal Creek members scooted south to Pelican Valley, about 20 miles away. Their pack grew and in 2000 was renamed to honor Mollie Beattie, the late director of the US Fish and Wildlife Service, who had been instrumental in the return of wolves to Yellowstone.
Bison are a part of, but not all of, the Mollie's diet, since prey varies seasonally in their Pelican Valley territory. The Mollie's bring down elk when they are available: from June through early November up to 80% of the pack's diet is elk. Once winter arrives and elk leave, the pack has two choices, according to a Yellowstone Wolf Project annual report.
First, they can travel to the elk. That's why they return to the Lamar Valley each December. During some years they stay longer than during others. In 2012, for example, when they began the year as the largest pack in Yellowstone, they remained for much of winter and spring.
The Mollie's second option is to switch to bison. Bringing down a bison-an animal ten times heavier and armed with sharp horns and deadly hooves-is dangerous and may take days. To improve their odds of success, the pack sorts and sifts, seeking a vulnerable animal. Bison are most vulnerable during winter, and from January through April at least 80% of the Mollie's diet is bison.
We hope that you enjoy this short video that Mary produced of the Mollie's demonstrating a skill the pack developed out of necessity. And a skill that no other pack in Yellowstone uses regularly on bison.
Rick Lamplugh lives near Yellowstone's north gate and is the author of the Amazon Bestseller In the Temple of Wolves: A Winter's Immersion in Wild Yellowstone. Available as eBook or paperback. Or as a signed copy from the author.
Photo of Mollie's around bison by NPS