I’m reading a new book on biogeography, Here Be Dragons, by Dennis McCarthy. It’s a popular-science introduction to the field, designed to show how evolution, along with plate tectonics and other changes in the configuration of land and sea, can explain the puzzling distributions of plants and animals on our planet. It’s worth a read, though a bit light on data and sometimes purplish in the prose.
Anyway, McCarthy mentions an amazing hunting behavior of orcas (Orcinus orca, also called killer whales), and gives a YouTube URL for the behavior. I’ve put the video below. Here you see a group of orcas pursuing a seal who’s taken refuge on an ice floe. The whales band together and head toward the floe, creating a bow wave that washes the seal into the water, ready for consumption. This video, however, has a happy ending: