We have in the USA three types of bear ,polar bear[isbjorn] black bear and brown bear .Brown bears are also found in europe and into Siberia. Here we often call the brown bears 'grizzly'bear.The brown bear is found in the west, and up into Alaska where the browns that inhabit Kodiak Island are called Kodiak bears and these are very large since they have large amounts of food available along the coast.The hump on their back [shoulders] are the muscles that they use for digging roots and their favorite ground squirrels.They are about 800-1200 pounds though there used to be one in a zoo that I saw that was 2000 !!!! He was enormous, with claws like bananas .Search through the forum and you'll see photos that will give you an idea of size and color.

Please sort this out for me..
It might be a stupid question, but here goes:
Are the brown and the grizzly bear different species..?
I thought so.. But in a book I`m reading (written by a norwegian adventurer) he claims them not to be..
Can anyone tell me more about the differences in size and colour, were they live and how they behavie..
Thanks!

Biologically speaking the Brown Bear and Grizzly are exactly the same species. Where they live depends and who is drawing the line makes the difference. In Canada they are all Grizzlies but just across the border they become Brown Bears. Safari Club claims the bears over 75 miles from the ocean are Grizzlies and those closer are Brown Bears. Boone and Crocket draw a line across Alaska and those on one side are Grizzlies and those on the other Brown Bears. As bears often wander a 100 miles They can be a Grizzly one day and a Brown Bear the next.
Basically Brown Bears are very well fed Grizzlies.Grizzlies have been seen over 400 miles off shore on pack ice with polar bears and here is even some evidence that Brown/Grizzlies even interbreed with Polar Bears and the offspring are viable. By definition that makes them all the same "species" Like Black Bears, (which they are not related to) there can be a lot of variations in size and color.