Fin whales (Balaenoptera physalus) are the 2nd largest living mammals on our earth, just after blue whales. When you consider that the average fin whale needs to hurl. It’s 80+ tons and 89+ feet out of the water and into the air, the spectacle becomes even more incredible.
As one of the fastest whales in the world, the Fin Whales can reach cruising speeds of 23 mph with short bursts up to 29 mph.
The Sei whale may beat it for short sprints up to 40mph, but not for cruising speed. They are remarkable speed has given Fin whales the nickname “greyhounds of the deep.” Fin Whale’s appearance is 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 are found in all the oceans of the world, but their migration process is not well understood. In the Southern Hemisphere, fin whales migrate south to feed on krill and other plankton in the summer. And north to likely give birth in warm waters closer to the Equator in the winter. Though, it is not well defined whether all of the population engages in this migration every year.
In the Northern Hemisphere, there are related north-south migrations. Several whales appear to return to the same feeding grounds every year. But the pattern is not so clear-cut, maybe because of the influence of the Gulf Stream in the North Atlantic. Populations of northern and southern hemispheres never meet.
Fin Whale has been sternly impacted worldwide by commercial whaling. When about more than 750,000 animals were killed in areas of the Southern Hemisphere. Only between 1904 and 1979, and they’re rarely seen these days. They are current status is unidentified in most areas outside of the North Atlantic.
Fin whale’s colors are dark grey to brownish-black, with pale or white undersides. Some fin whales have a pale grey chevron on each side behind the head. There may be a dark stripe running up and back from the eye, and a light stripe arching down to where the flipper joins the body.
This mammal has a unique characteristic among mammals, famous as asymmetrical pigmentation. The lower right jaw is bright white, and the lower-left jaw is black. The reason for this unusual coloring is unidentified. But specific researchers have speculated that fin whales circle schools of fish with the white side facing the prey and frightening them into denser schools that are easier for the whale to catch.
Fin whales are pelagic and coastal species. Sometimes occurring in shallow waters (30 m), most are observed as single animals, but sometimes seen in pairs or groups. Young fin whales nurse for 6-7 months and sexual maturity is reached between 6 to 11 years. The lifespan of a fin whale is around 85 to 90 years.
It has been assumed that breeding occurs in warm waters, but no exact breeding grounds have been observed. Females give birth every 2-3 years and the gestation period is 11 to 11.5 months. In winter and autumn, there’s no feeding, and whales are found in lower latitudes.
Herring, capelin, and other shoaling fish are eaten in both the North Atlantic and North Pacific. Along with squid, euphausiids, and copepods which are small crustaceans. The fin whale, like other baleen whales, strains its food from the water through baleen plates.