Some form of brood parasitism, maybe? I mean it is known that orcas hunt whale calves and presumably this involves an instinctive reaction from the adults to th

Some form of brood parasitism, maybe? I mean it is known that orcas hunt whale calves and presumably this involves an instinctive reaction from the adults to the calf's distress signal. So perhaps various other preys have learnt to imitate this distress call in order to gain protection from what are possibly the only animals in the sea capable of fighting an orca. Or maybe whales just hate orcas and want them to starve.