Coastal Research and Education Society of Long Island
Coastal Research and Education Society of Long Island

Fin Whales


Fin Whales

Fin whale (Balaneoptera physalus)

Fin whales are the second largest species of whale and the second largest animal ever to have lived. Fin whales (also know as finback whales) can reach lengths of over 80 feet and weights of more than 160,000 lbs in the northern hemisphere and over 85 feet and 170,000 lbs in the southern hemisphere and are distributed around the world except for the tropics, i.e., they have an antitropical distribution.

  • Fin whales are listed as endangered throughout their range in the Endangered Species Act.  In November 2018, the status of fin whales on the IUCN redlist, with an estimated global population of 100,00 adults, was changed from Endangered to Vulnerable! 

Fin whales feed on a wide array of prey species, depending upon availability, ranging from small schooling fish such as sand eels, herring and tinker mackerel, to crustaceans such as krill and copepods, to squid. A variety of feeding techniques are employed in order to concentrate prey, essentially fin whales are "gulpers," taking in large quantities of food and water in each mouthful.

Fin whales are extremely fast, sleek, muscular whales, sometimes referred to as "the greyhounds of the sea" because of the great speed that they can reach (>25 knots).

Fin whales get their name from the very prominent and falcate (curved) dorsal fin, situated around 2/3 of the way back from the head. There are 6 different dorsal fin shapes and we use them to help identify individuals.

falcate dorsal fin of fin whale

Fin whales also have a distinctive V-shaped pattern of coloration around their heads called chevrons and may also have dark eye stripes and ear stripes which form a pattern called a blaze. Dorsal fin shape, chevron and blaze patterns, and scars can be used to identify individuals.

Right side of fin whale's head showing coloration pattern

Chevron of fin whale is more prominent on the left side

Fin whales have asymmetrically colored jaws and baleen plates. The right side lower jaw and the baleen on its tip are white, while the left side are dark. This pattern can be seen occasionally in minke whales (Balaenoptera acutorostrata), but EVERY fin whale exhibits this asymmetry. Although there are many hypotheses, we still have no definitive idea as to the function of the asymmetrical coloration.

AHK_3976_left__chevron.jpg

The ventral surface of the body, flukes, and flippers are white, and the rest of the body is dark gray to brown.

 Fin whale calf showing its white lower jaw

 To date, CRESLI had identified 165 different fin whales in the waters off Montauk since 2009.