Distribution is worldwide: the blue, fin, humpback, and the sei whales are found in all major oceans; the common (northern) and Antarctic (southern) minke whale species are found in all the oceans of their respective hemispheres; either of
Bryde's whale and
Eden's whale occur in the
Atlantic,
Pacific, and
Indian oceans, being absent only from the cold waters of the
Arctic and
Antarctic; and the gray whale is found in the northern Pacific Ocean, although it was also found in the Atlantic Ocean in historic times.
Rice's whale has the smallest distribution of rorquals and possibly baleen whales in general, being
endemic to a small portion of the
Gulf of Mexico west of the
Florida peninsula and south of
Alabama and the
Florida panhandle, although it likely formerly had a much wider distribution in the Gulf. Most rorquals are strictly oceanic: the exceptions are the gray whale, Bryde's whale, Eden's whale, and Rice's whale (which are usually found close to shore all year round) and the
humpback whale (which is oceanic but passes close to shore when migrating). It is the largest and the smallest types — the blue whale and Antarctic minke whale — that occupy the coldest waters in the extreme south; the fin whale tends not to approach so close to the ice shelf; the sei whale tends to stay further north again. (In the northern hemisphere, where the continents distort weather patterns and
ocean currents, these movements are less obvious, although still present.) Within each species, the largest individuals tend to approach the poles more closely, while the youngest and fittest ones tend to stay in warmer waters before leaving on their annual migration. Most rorquals breed in tropical waters during the winter, then migrate back to the polar feeding grounds rich in
plankton and krill for the short polar summer. == Feeding habits ==