Whale Alert – West Coast

Whale Alert – West Coast

Fin whale

Balaenoptera physalus

The fin whale is the second largest whale, mammal, and animal on earth.  Despite its massive size, it is considered the “greyhound of the sea”, being able to sustain speeds of 37 to 40 kph (23 to 25 mph).

Conservation status

Appearance

As the second largest animal on earth, only to the blue whale, fin whales reach a maximum length of 26 m (88 feet) and weigh up to 72,000 kg (80 tons).  They are slender with a girth that is 40 to 50 percent of its length.  Their head is flat and V-shaped with a central ridge sweeping back toward a splash guard around twin blowholes.  Its flippers are tapered and short, its flukes are notched and broad but narrow.  The coloring of its body is gray or gray-brown above and whitish below along with its flippers and fluke.  It has a distinct asymmetrical coloration in the face with a black lower left jaw and whitish coloring on the right side.  A chevron pattern that is lighter in color runs behind the blowholes toward the tail and then sometimes reverse, running back toward the head.  These chevrons can be distinctive among individuals and serve as a way to identify individual fin whales.

Distribution and migration

Fin whales are found in all the world’s open oceans.  Like other large whales, they migrate between their northern summer feeding grounds and their southern winter breeding and calving grounds.  Migrations between these two places occurs in the open ocean, so timing and routes are not well mapped.  It is known that pregnant females usually arrive first at summer feeding areas, but winter breeding and calving locations are still unknown.  Year-round presence has been noted off central and southern California that peaks in summer and fall.  Acoustic surveys off the west coast have recorded fin whale calls year-round, with the highest concentration from September to February.

Habitat

Fin whales are mostly seen in areas of high productivity in temperate and coastal waters near the continental shelf and slope, in waters ranging from 77 to 3,200 m (252 to 20,506 feet) deep.  They exist in a wide range of sea temperatures from 5 to 28 degrees C (41 to 82 degrees F).  Peak abundances of whales in the Southern California Bight have been recorded following periods of maximum upwelling.

Feeding style and diet

The food of fin whales can be quite diverse, likely reflecting seasonal and local conditions.  They are a lunge-feeder, preying upon schooling fish, small squid, and crustaceans like krill and copepods.  In the Northern Hemisphere, they eat anchovy, herring, capelin, mackerel, sardine, hake, and sand lance. 

 Other common species found on the west coast

Blue whale     Humpback whale    Minke whale    Gray whale    Killer whale

Learn more

Want to learn more about whales along the west coast? 
Check out the Field Guide to MARINE MAMMALS of the Pacific Coast, a California Natural History Guide by Sarah G. Allen, Joe Mortenson, and Sophie Webb.