Predator-informed looming stimulus experiments reveal how large filter feeding whales capture highly maneuverable forage fish

Significance Rorqual whales include the largest predators of all time, yet some species capture forage fish at speeds that barely exceed their quarry, suggesting that highly maneuverable fish should easily escape. We found that humpback whales delay the expansion of their jaws until very close to schools of anchovies, and it is only at this point that the prey react, when it is too late for a substantial portion of them to escape. This suggests that escape responses of these schooling fish, which have evolved under pressure from single-prey feeding predators for millions of years before the advent of lunge feeding, are not tuned sufficiently to respond to predators that can engulf entire schools, allowing humpback whales flexibility in prey choice.