The Kodiak (brown) bear was named for its being endemic to an area centering on Kodiak Island, off the south coast of Alaska. However, the Kodiak bear is also found on other nearby Alaskan islands such as Admiralty and Shuyak, where, as on Kodiak, it has developed within an isolated genetic niche based on an abundance of high protein food, namely salmon. As a result, the Kodiak is much larger than the grizzly bear of the Rocky Mountains, and the fact that the range of the Kodiak is so confined by island status and diet has meant that there is nothing to dilute its biological and genetic response to its very protein-rich diet.
With a general biology very similar to that outlined for the interior grizzly, the Kodiak bear is often the subject of debate over which is the biggest species of bear. It is often held that the polar bear, which is, in many ways, the most mythologised bear, is the biggest and most ferocious ursid, but there is in fact very little difference in the potential size and bulk of the two species. The term 'potential' is very important here, as even in a particular age/sex class, height and weight variability among North American bear species can be extreme. If anything, the average highest weights amongst Kodiaks are higher than those amongst polar bears, though individual polar bears may exceed the average high weight of Kodiaks by a significant amount. This said, it is difficult to compare bears' weights because of extreme seasonal fluctuation: Kodiaks have a longer feeding period than polar bears, and the point at which the two species are at their maximum weight is a narrow intersection. Comparison at that point might be interesting, but may not mean very much, perhaps giving a false overall impression of the polar bear, whose extreme fat diet over a relatively short time results in a very variable annual weight change. This begs the question of when meaningful comparison might be made, and that perhaps comparison is not very important, but is too much of an issue in our statistics-hungry minds where it simply serves to propagate myth and misunderstanding. For more points and discussion about issues like this, go to the Myths and Legends section of this website.
In the wilderness is the salvation of the world.
Henry David Thoreau