Fin Whale

Fin Whale, enormous, sleek-bodied, and streamlined whale. The second largest animal on earth, the fin whale is exceeded in size only by its close relative, the blue whale. Named for its dorsal fin, which rises approximately 60 cm (2 ft) high, an adult fin whale will reach a length of 18 to 25 m (59 to 82 ft) and a weight of 30 to 80 tons.

Ranging almost worldwide, fin whales travel in schools of up to 100 members and are most common in the southern hemisphere. Some populations summer in cold waters abundant with krill—tiny, shrimplike crustaceans favored as food by fin whales—and migrate to warmer waters during the winter to bear calves and breed. For example, in the North Pacific, fin whales range from the Bering Sea to Baja, Mexico. Generally, these whales avoid extreme climates and conditions, such as very warm equatorial waters or polar ice packs.

Fin whales have a wedge-shaped head with a flat top. They have a distinct ridge along their back from the backward-sloping dorsal fin to the broad, triangular tail flukes (tail lobes). Due to their streamlined shape, fin whales are fast swimmers, reaching speeds of over 30 km/h (19 mph). Like most whales, fin whales have dark gray or brownish black backs and white undersides. They are distinguished by their harlequin coloring: the right side of their head, jaws, and baleen (cartilaginous, teethlike plates) is white, and the left side of their head is slate black. This unusual pigmentation may result from the fact that fin whales swim on their side while hunting for fish. Some scientists theorize that the light head and baleen area, against the dark ocean background, gives the illusion of an opening. When small fish try to escape through this opening, they swim straight into the whale’s mouth. The fin whale’s blow (exhaled stream of air and water) is tall and narrow, reaching about 4 to 6 m (13 to 20 ft) high.

Like other baleen (toothless) whales, fin whales feed primarily on krill, using the sievelike lower fringe of the baleen plates to strain the tiny organisms from the water. Fin whales also catch squid and a variety of fish, including anchovies and herrings.

Particularly when feeding or breeding, fin whales engage in a wide array of playful antics—including breaching (leaping completely out of the water), wrestling with each other, and slapping the water vigorously with their large tails. These activities not only build strength and agility but also prepare the whales for self-defense. Fin whales, for example, will use their powerful tail flukes to counterattack killer whales, their primary predators after humans.

Females typically give birth to a single calf after migrating to warmer waters, nearly one year after mating. Newborn calves are sizeable, weighing more than 2 tons and reaching up to 6 m (20 ft) in length. Like other baleen whale offspring, calves nurse for approximately six months—until the baleen is fully formed and they can feed themselves.

For centuries, fin whales were often able to outswim sail-powered whaling ships and avoid capture. Fin whales also sometimes smashed early whaling boats into splinters. Once the steamship and power harpoon were invented, however, fin whales lost their physical advantage. Large-scale hunting over the past 100 years has resulted in a population drop from about 450,000 whales to fewer than 120,000 worldwide. Fin whales are not considered endangered, but they are protected from commercial whaling—as are all whales. By international agreement, however, native Greenlanders will be allowed to catch 19 fin whales each year from 1998 through 2002 as a means of sustaining their cultural practices.

Scientific classification: The fin whale is a member of the rorqual family, Balaenopteridae, in the order Cetacea, suborder Mysticeti. It is classified as Balaenoptera physalus.

Fin Whale Microsoft® Encarta® Encyclopedia 2001. © 1993-2000 Microsoft Corporation. All rights reserved.