How do polar bears defend themselves from orcas/killer whales?

Orcas are not opportunistic feeders. In the same way that orcas don't attack humans, they also don't prey on othe creatures not on their normal diet 'list'. read more

They don’t, but then again, they don’t really need to, because Orcas have little interest in eating a polar bear (and would probably have a hard time digesting one). No question, an Orca is a much bigger and more powerful animal, but they have little reason to harass a polar bear. read more

"The primary predators of whales are killer whales, certain species of sharks—like the tiger shark or the great white shark—and the polar bear, which occasionally hunts beluga whales in the Arctic. read more