01/30/2022
Grizzly bears in the Greater Yellowstone Ecosystem have a very high percentage of in meat in their diet compared to the diets of other bear populations (40% meat and 60% vegetation). This can be attributed to the large concentrations of ungulate species living inside the ecosystem such as: elk, bison, mule deer, whitetail deer, pronghorn, big horn sheep, and moose. For comparison meat provides as little as 3% of a grizzly bears diet in Glacier National Park and Denali National Park.
The generalist diet of Yellowstone grizzly bears enables them to feed across diverse habitats and adjust to seasonal/ yearly variations in the availability of food.
Like humans, grizzly bears are omnivores and are generalist feeders in which anything that is palatable may be part of their diet.
They have been documented eating 175 different plants, 37 invertebrates, 34 mammals, seven birds, and four species of fish.
This flexibility in their diet allowed them to once roam all over North America from the great plains westward to California and central Mexico north throughout Alaska and Canada. Today, the grizzly bear is found in only about 2 percent of its original range in the lower 48 states.
All photographs were taken on tour in the summer of 2020.
