Assertion: polar bear's predator | /r/HasProperty | killer whales
Facets:
Source sentences:
text: The main predators of seals are killer whales, polar bears, leopard seals, large sharks, and human beings.
text: In fact, polar bears are so high up on the food chain that their only known predator is the killer whale.
text: The only predators of Polar Bears are humans, killer whales and occasionally other Polar Bears.