Grizzly (Ursus arctos horribilis) - Yellowstone National Park, WY. Grizzlies are normally solitary active animals, but in coastal areas the grizzly congregates alongside streams, lakes, rivers, and ponds during the salmon spawn. Every other year, females (sows) produce one to four young (commonly two) which are small and weigh only about 500 grams (one pound). A sow is protective of her offspring and will attack if she thinks she or her cubs are threatened. Grizzly Bears are very aggressive animals that will take anything as a threat.
This Grizzly was actually still with his brother who is just ahead of him. They were still quite friendly with each other, this will not be the case when they start competing for females. If I had not talked with a local photographer and a park ranger who were familiar with this pair, I would not have been able to learn about these guys. When my brother and I came across these two they were just having some fun by putting the run on some full grown bison, it was a lot of fun watching them sneak through the trees and then charge the bison. After they did this several times they wandered off together.