There is a world somewhere between reality and fiction. Although ignored by many, it is very real and so are those living in it. This forum is about the natural world. Here, wild animals will be heard and respected. The forum offers a glimpse into an unknown world as well as a room with a view on the present and the future. Anyone able to speak on behalf of those living in the emerald forest and the deep blue sea is invited to join.
I do not find it difficult to imagine a huge male tiger ambushing and killing a large mature male brown bear. The big tiger would obviously be very confident; likely feared by other tigers. Big Mature male brown bears are probably killed occassionally by tigers, although I feel certain that, even when Siberian wildlife was more heavily populated and tigers were not so rare, this was a very rare event. Tigers can in some cases, as has been mentioned on this site, grow to prehistoric dimentions, as does the brown bear on occassion. I will mention though, that there is a difference between an ambush attack and a face-to-face confrontation. But, I will agree that the tiger is, in my opinion, the greatest terrestrial predator on this planet.
I will be looking for that book on Amazon. Thank you Peter for the information.