Primarily their range and diet. Following that their average size, population density, and tactical behaviors. After that the “cultural” characteristics affecting semi-isolated populations...such as the coat color of the Toklat Grizzly, or the perceived aggression of hard living interior bears, or the passive tolerance of fat and happy coastal ones. I believe the North American Grizzly is pretty much the same animal from Nome, Alaska to Jackson Hole, Wyoming aside from that. I’ve read that the Kodiak Brown Bear has been genetically isolated long enough to be distinct on a subspecies level...but that mainland bears and those from the near shore islands of south-east Alaska, aside from those superficial differences, are less distinct.
