Large animal photography

I am visiting Canada from Australia in October and am basing the entire trip around the amazing Canadian wildlife. I am just wondering what the general recommendations are around photography the mammals there (with animal welfare at the forefront)?

I would love to photograph animals such as bears, moose, elk, beavers etc etc but I’m worried about the ethics side of things.

I have a 100 - 400mm lens but am willing to get a bigger lens or a 2x extender to maximise distance. Obviously I don’t plan on getting close to any of these animals (for their sake and mine) but was just wondering what all other photographers do to still have amazing encounters and get great shots, without disturbing the animals and being unethical tourists?