Fin whales are the second-largest species of whale, with a maximum length of about 75 feet (22 m) in the Northern Hemisphere, and 85 feet (26 m) in the Southern Hemisphere. Fin whales show mild sexual“dimorphism”, with females measuring longer than males by 5-10%. Adults can weigh between 80,000-160,000 pounds (40-80 tons).
Fin whales have a sleek, streamlined body with a V-shaped head. They have a tall, “falcate” dorsal fin, located about two-thirds of the way back on the body, that rises at a shallow angle from the animal’s back. The species has a distinctive coloration pattern: the back and sides of the body are black or dark brownish-gray, and the ventral surface is white. The unique, asymmetrical head color is dark on the left side of the lower jaw, and white on the right side. Many individuals have several light-gray, V-shaped “chevrons” behind their head, and the underside of the tail flukes is white with a gray border.
Fin whales can be found in social groups of 2-7 whales and in the North Atlantic are often seen feeding in large groups that include humpback whales, minke whales, and Atlantic white-sided dolphins(Jefferson et al. 2008). Fin whales are large, fast swimmers and the killer whale (Orcinus orca) is their only non-human predator.
During the summer, fin whales feed on krill, small schooling fish (e.g., herring, capelin, and sand lance), and squid by lunging into schools of prey with their mouth open, using their 50-100 accordion-like throat pleats to gulp large amounts of food and water. They then filter the food particles from the water using the 260-480 “baleen” plates on each side of the mouth. Fin whales fast in the winter while they migrate to warmer waters.
Little is known about the social and mating systems of fin whales. Similar to other baleen whales, long-term bonds between individuals are rare. Males become sexually mature at 6-10 years of age; females at 7-12 years of age. Physical maturity is attained at approximately 25 years for both sexes. After 11-12 months of gestation, females give birth to a single calf in tropical and subtropical areas during midwinter. Newborn calves are approximately 18 feet (6 m) long, and weigh 4,000-6,000 pounds (2 tons).
Fin whales can live 80-90 years. The age of large whales in family Balaenopteridae can be estimated by counting the layers present in waxy ear plugs, which are formed in the auditory canal (Hohn 2002).
|80,000-160,000 pounds (40-80 tons)|
|75-85 feet (22-26 m)|
|sleek, streamlined body; distinctive coloration pattern: the back and sides of the body are black or dark brownish-gray, and the ventral surface is white|
|krill, small schooling fish (e.g., herring, capelin, and sand lance), and squid; they fast in the winter|
|found in social groups of 2-7 whales; fast swimmers; little is known about their social and mating systems|
OTHER NAMES: Finback, Common Rorqual, Razorback
NEIGHBORING SPECIES: Most marine species. Humpback, Blue and Sperm whales have similar distributions. The sperm whale is also found in coastal waters.
PREDATORS: Humans, Killer Whales
THREATS: Ship strikes. Ship strikes occur with Fin Whales more than any other species of large whales. Disturbance from low-frequency noise, net entanglement, habitat degradation, and reduced prey due to over fishing.
DIET: Krill and small schooling fish such as herring, capelin, and sandlance.
MANNER OF FEEDING: Lunging into schools of krill and fish. They are often observed feeding with Humpback Whales, Minke Whales and Atlantic White Sided Dolphins.
BEHAVIOR: Travel alone or in small pods. They are the fastest of the large whales. Due to their speed, they can leap completely out of the water. Breaching and spy hopping is very common. These whales will often chase one another. This is believed to be courtship behavior.
REPRODUCTION: Little is known about their mating patterns. Calving occurs in the winter months after a 11-12 month gestation period. The calf will stay with the other for 6-8 months. Females usually give birth every 2-3 years. Twins are occasionally recorded in utero, but there is no recorded of both surviving. Mating with Blue whales has been recorded.
LIFE SPAN: At least 80 years
Habitat: Fin whales are found in deep, offshore waters of all major oceans, primarily in temperate to polar latitudes, and less commonly in the tropics. They occur year-round in a wide range of latitudes and longitudes, but the density of individuals in any one area changes seasonally.
There are two named subspecies of fin whale:
- B. physalus physalus in the North Atlantic
- B. physalus quoyi in the Southern Ocean
There is also a population of fin whales in the North Pacific, which most experts consider a separate, unnamed subspecies. These populations rarely mix, if at all, and there are geographical stocks within these ocean basins. Fin whales are migratory, moving seasonally into and out of high-latitude feeding areas, but the overall migration pattern is complex, and specific routes have not been documented. However, acoustic recordings from passive-listening hydrophone arrays indicate that a southward “flow pattern” occurs in the fall from the Labrador-Newfoundland region, past Bermuda, and into the West Indies (Clark 1995). There may be resident groups of fin whales in some areas, such as the Gulf of California, the East China Sea, and the Mediterranean Sea.
Although reliable and recent estimates of fin whale abundance are available for large portions of the North Atlantic Ocean, this is not the case for most of the North Pacific Ocean nor for the Southern Oceans. The present status of populations in these ocean basins relative to their pre-whaling population size is uncertain.
For management purposes, fin whales in U.S. waters have been divided into four stocks:
- Alaska (Northeast Pacific)
- Western North Atlantic
The most recent stock assessment reports with population estimates are available on our website.
- historically, commercial whaling
- collisions with vessels
- entanglement in fishing gear
- reduced prey abundance due to overfishing
- habitat degradation
- disturbance from low-frequency noise
Commercial whaling for this species ended in the North Pacific Ocean in 1976, in the Southern Ocean in 1976-77, and in the North Atlantic Ocean in 1987. Fin whales are still hunted in Greenland and subject to catch limits under the International Whaling Commission’s “aboriginal subsistence whaling” scheme.
The possibility that illegal whaling or resumed legal whaling will cause removals at biologically unsustainable rates is also considered a threat.
Of all species of large whales, fin whales are most often reported as hit by vessels (Jensen and Silber, 2004 [pdf]).
Schooling fish constitute a large proportion of the fin whale’s diet in many areas of the North Atlantic, so trends in fish populations, whether driven by fishery operations, human-caused environmental deterioration, or natural processes, may strongly affect the size and distribution of fin whale populations.
The Atlantic Large Whale Take Reduction Team was established to develop a plan to reduce the incidental serious injury and mortality of fin whales, right whales, humpback whales, and minke whales in the South Atlantic shark gillnet fishery, the Gulf of Maine and Mid-Atlantic lobster trap/pot fishery, the Mid-Atlantic gillnet fishery, and the Gulf of Maine sink gillnet fishery. For more about the Atlantic Large Whale TRT, please visit the ALWTRT page on our Greater Atlantic Regional Office website.
The 2007 IUCN Red List of Threatened Species lists fin whales as “endangered.”
Within the U.S., the fin whale is listed as endangered throughout its range under the Endangered Species Act of 1973 and is listed as “depleted”throughout its range under the Marine Mammal Protection Act of 1972.
- Barlow, J. 2003. Cetacean abundance in Hawaiian waters during summer/fall 2002. Admin. Rep. LJ-03-13. Southwest Fisheries Science Center, National Marine Fisheries Service, 8604 La Jolla Shores Drive, La Jolla, CA 92037.
- Clark, C.W. 1995. Application of US Navy underwater hydrophone arrays for scientific research on whales. Rep. int. Whal. Commn 45:210B212.
- Hohn, A.A. 2002. Age Estimation. pp. 6-13. In: W.F. Perrin, B. Würsig, & H. Thewissen (eds.) Encyclopedia of Marine Mammals. Academic Press, San Diego, CA.
- Jefferson, T.A., M.A. Webber, and R.L. Pitman. (2008). Marine Mammals of the World, A Comprehensive Guide to their Identification. Amsterdam, Elsevier. Pp. 47-50.
- Jensen, A.S. and G.K. Silber. 2003. Large Whale Ship Strike Database. U.S. Department of Commerce, NOAA Technical Memorandum. NMFS-OPR-25, 37 pp.
- Individual fin whales can be identified by the pattern of chevrons and streaks of lighter coloration on their back, in addition to the size and shape of their dorsal fin.
- The asymmetrical coloration pattern on the head of fin whales is reversed on their tongue.
- Fin whales sometimes mate with blue whales and hybrids have been documented.
- They are often called the “Greyhound of the Oceans” because of their fast speed (up to 25mph).
- The Fin Whale’s jaw is black on one side and white on the other.
- They get the name “Razorback” from the sharp edge of the caudal peduncle (just behind the dorsal fin).
- Unlike other baleen whales, they rarely raise their flukes out of the water when diving.