Because science

If by some weird quirk of fate you are ever offered undercooked black bear meat and told not to worry about it, trichinosis only affects grizzly bears,
DON'T EAT IT.
I am serious, people. A woman just came in today and told me that she has been eating rare bear steaks for a year because she believed this snippet of advice from a community elder (she doesn't live here.) Which is startling and worrying. Yes, traditional knowledge has a lot to offer, but don't accept a pronouncement lock, stock and barrel when acting on it can put your life at risk. People are people, and people make mistakes. If you don't believe me, read this guy's story:
http://www.adn.com/article/20121025/dinner-black-bear-leads-rare-trichinosis-infection-nikiski-man