Gray Whales don't find much food along the migration trail, but this is a lucky whale! Grays specialize in feeding on amphipods in the silt and muddy bottom of the Arctic seas, so they are very different when feeding at the surface. A rare sight, feeding at the surface is called skim feeding. Whales open their mouths and skim tiny shrimp-like krill near the surface. This rare feeding behavior can happen when there's an upwelling of nutrient-rich water and an abundance of krill—a scrumptious treat on migration!