Marine ecologist Robert L. Pitman has spent years studying the killer whales of the Antarctic. As I recounted in Shadows of Existence, he believes there may be three species, not one. Here he discusses a particular population that has learned to follow an icebreaker for the food it gives access to. He also recounts an incident where he playfully threw a snowball at a whale - and the whale began flipping a chunk of ice into the air with its nose. Fascinating stuff.
Note; The term "killer whale" was popular for a long time, was largely replaced by the less prejudicial "orca," and seems to be slipping back into proper use. (Who decides these things?)