Originally Posted by Tombstone RJ
Grizzlys and Kodiaks are brown bears. Not sure about Bruins.
All of the brown bears found in much of the northern hemisphere are closely related, including both North American and European species. In all likelihood they should be treated as a single species (Urus arctos), even though sometimes listed as several separate species, with a number of distinct subspecies. There is quite a bit of disagreement about the number of subspecies, but genetic testing is making the classification of the brown bear much clearer. There are a number of generally agreed upon subspecies, these include the and the European Brown Bear, Himalayan Brown Bear, the Syrian Brown Bear, Mexican Brown Bear, Hokkaido Brown Bear, the Kodiak Bear and the Grizzly. The polar bear is a very close relative of this group and could be considered a subspecies as well, hybrids are possible.
For the most part the subspecies are differentiated by size, some, each has adapted to the various environments with southern subspecies generally being smaller than northern counterparts. This reflects available prey and food availability. The king of the group is the Kodiak Bear which can reach as much as 1,500 lbs and up to 10ft in height, with occasional individuals larger than this. The large size of Kodiak and Alaskan Grizzlies stems from the availability of salmon, an extraordinarily rich and reliable food source. A Kodiak Bear is the largest land predator currently living on our planet.