This asymmetry of pigmentation is also shown on the tongue. Finback Whales are occur in small groups or may be solitary. They are typically whales of the open seas and are found in all oceans. They are very fast-swimming whales, and show similar migratory habits to Blue Whales, with a general northwards movement of southern animals into warmer waters for breeding during the southern winter season. However, Finbacks return to the Antarctic somewhat later than Blue Whales.
Finbacks eat small crustaceans and schooling fishes such as herring, together with squid.
Like other whalebone whales, Finbacks feed by using their baleen, the fringed plates on both sides of the mouth, as a strainer. There may be over four hundred plates on each side, each some seventy centimetres long. These plates are on the upper jaws only. The lower jaws are bowed outwards, and are joined together by ligaments at their front ends, to give some flexibility of movement. The throats of whalebone whales are grooved, longitudinally, indicating the presence of pleats that allow an enormous expansion of the throat cavity when water is taken in.