FIN WHALE
Balaenoptera physalus
(Linnaeus 1758)

Also called Razorback, Finner, Finback, Common Rorqual, and the Greyhound of the Sea.

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The fin whale is second in size only to the blue whale, the largest whale at 100 feet.  For an animal that weighs up to 80 tons and may reach a length of 80 feet, the streamlined fin whale is an amazingly swift swimmer.  It swims at 5-15 miles an hour with faster bursts of speed.  One fin, radio-tagged off of Iceland, traveled 1860 miles in 10 days or approximately 200 miles per day.

The fin is a remarkably deep diver and can reach depths of up to 700 feet.  Unlike blue or sei whales, they do not show their flukes when beginning a dive, although they may arch their backs and raise their tail stock. The back has distinct ridges from the dorsal fin to the flukes which accounts for the name “razorback.”

The fin whale’s most distinctive feature is their unique coloring which is unlike any other whale. Its color is light gray to brownish black on its back and sides.  It has lighter colored chevrons which begin behind the blowholes and slant down the sides towards the tail before turning and ending right behind the eye.

The right lower lip, including the mouth cavity and right front baleen, are white or yellowish-white.  Remaining baleen plates on the right and those on the left are striped with alternate bands of yellowish white and bluish gray.

The purpose of this unusual coloration is thought to play a part in fin feeding strategy. They have been observed swimming toward their prey, rolling on their right side, pivoting in a tight turn, and opening their mouths.  Perhaps this allows the whale to take advantage of its white side to scare and concentrate fish. Fins eat an assortment of foods, including krill, fish and squid.

Sexual maturity occurs between 6-10 years of age.  After a 12-month gestation period, females give birth every two to three years to a 20-foot, two-ton calf which is weaned between six-eight months.  Most mature animals are in the 70-80 foot range, with females slightly larger than males. 

Fins are usually found in small pods of 3-7 animals, but single animals have also been observed. They may form groups of 100 or more on feeding grounds.

Fin whales have a worldwide distribution.  They move  toward both poles in the spring and to warmer waters in the fall, as do most other large baleen whales.

Unlike blue or sei whales, fins occasionally breach.  They do not re-enter the water headfirst and smoothly, but with a big splash. Their cone-shaped blow is very tall, 15-20 feet, and can be seen from a great distance.

Fin whales’ natural enemy is killer whales (orcas).  Fins  did not become an important commercial whale until the early 1950s with the development of fast catcher boats. After the severe depletion of the blue whale, especially in the Antarctic, whalers turned their sights on fins, reducing their numbers in most areas. Their present population is estimated at 40,000 in the northern hemisphere and 15,000 to 20,000 in the southern hemisphere which is a small percent of their original population.