Going back through some of Swedish filmmaker (FORCE MAJEURE, PLAY) Ruben Östlund's past interviews, I found one where he references a nature documentary that has been very inspirational to him. It makes a lot of sense that a filmmaker so concerned with instinct and herd behavior should like this film.
Warning: predatory animal on animal violence. There's no shame at all if you don't want to see this kind of stuff. But if you've watched National Geographic-type documentaries it shouldn't shock you too much.