Funny, when growing up in Alaska I used to always hear the advice that if you ran into a brown / grizzly bear, you should climb a tree, but if it is a black bear, don’t bother. As the advice used to go, unlike black bears, brown bears had claws too long for them to climb trees.
Well I have seen so many brown bears over the years way up in trees to know that this advice is completely wrong. But, we have learned so much over the years Back then I was told grizzles and brown bears were two different species which DNA testing has since proven false. The bears in the interior of Alaska are smaller because of the more limited food source, not because they are a different species. Turns out, having access to high calorie salmon is helpful in growing big.
This was a sow with a couple of young cubs way up in a spruce on a rainy day this past June. Here she is watching a boar on the ground below. I will say, I haven’t seen any of the huge boars climbing trees so maybe they can’t. This probably isn’t lost on the sows.