Yellowstone grizzly bears now dine on dandelions instead of trash
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Yellowstone grizzly bears now dine on dandelions instead of trash

Barred from the dumps where they once chowed on trash, the grizzly bears (Ursus arctos) of Yellowstone National Park and surrounding areas have substantially cleaned up their diets over the past few decades, a new study shows. Hundreds of field observations of the bears feeding and analyses of grizzly scat reveal that the animals’ garbage consumption peaked in the early 1970s, as the number of visitors to the park increased, but declined to practically zero when trashcans were converted to a bear-proof design and municipal dumps in and around the park were shut down, researchers report in the current issue of Ursus. From 1968 to 1971, 36% of grizzly poop contained trash, but studies of scat collected from 2011 to 2013 have found little to none. Today, grasses, ants, and flowering plants such as dandelions dominate the grizzly diet, followed by berries, trout, and mammals such as elk, bison, and gophers. (Despite the bears’ fierce reputation, only seven people have been killed in the 143-year history of the national park.) The 266-item list of foods documented in the new study—including moths, algae, and even dirt—illustrates the bear’s ability to adapt to rapid changes in the abundance of their favorite foods, the researchers say.