What is the hunting technique used by orcas to knock seals off ice floes?

The hunting technique orcas use to knock seals off ice floes is called wave-washing.

In Antarctic waters, groups of killer whales coordinate their movements as they approach a seal resting on floating sea ice. They may form a line, swim rapidly toward the floe, and dive or roll in synchrony just before reaching it. The combined movement displaces enough water to send a wave over the ice, washing the seal into the sea, where other orcas can intercept it.

This is a striking example of cooperative hunting. The whales may repeat the maneuver several times, and larger floes can be cracked or broken into smaller pieces before the final wave dislodges the seal. The technique is associated particularly with Antarctic type B orcas, which hunt seals and other marine mammals.

The name is sometimes written “wave-washing,” “wave washing,” or described as “wave-hunting.” These labels refer to the same general strategy; “trapping,” “chase,” and “ambush” do not identify this specialized ice-floe attack.