Do black bears kill grizzly bears?

Black bears (Ursus americanus) and grizzly bears (Ursus arctos horribilis) are two distinct species of bears that overlap in range in North America. While both species are predators, black bears are typically smaller and less aggressive than grizzly bears. Black bears tend to avoid confrontations with grizzly bears, and there is no evidence to suggest that black bears kill grizzly bears.