what is the difference between brown bears and grizzly bears
Same goes for their size. Brown bears are larger than grizzlies due to their rich diet, not because of genetics. Zoo animals tend to be much larger than wild animals for the same reasons....not because they are any different genetically. Brown bears live from the coast to 50 miles inland and Grizzly Bears live from 50 miles inland to the interior. The only difference is their diet.
The Grizzly is a larger bear than the brown bear. It is often recommended that when you are in Grizzly territory, you wear bells on your clothing so that the jingling will allert the Grizzly that you are in the area and minimize the likelyhood of surprising one. They will usually run away if they know you are there.