herbivory Bison Grazing Yellowstone National Park Mouth Chewing Herbivory in Spring by Pronghorn Productions in Bison , Mammal , Ungulate Full HD (1920x1080) – $9 HD (1280x720) – $7 Add to Cart Checkout Added to cart Bison Grazing Yellowstone National Park Mouth Chewing Herbivory in Spring $9