Balaenoptera physalus - The Fin Whale

Balaenoptera physalus is commonly known as the fin whale, the finback whale or sometimes the razorback. After the blue whale it is the second biggest animal in the world, reaching a length of up to 85 feet, though there are reports of larger ones, and a weight of up to 82 short tonnes. The naturalist Roy Chapman Andrews called the fin whale "the greyhound of the sea... for its beautiful, slender body is built like a racing yacht and the animal can surpass the speed of the fastest ocean steamship." They get their Latin name from the fact that when they exhale, the spout is huge, bigger than other whales. Physa is the Greek word for ‘blow’. The common name fin or finback comes from the fact that its dorsal fin is more prominent than in other species, helping to identify them. But ultimately most cetaceans have dorsal fins and its name seems to imply that its fin is somehow a unique feature – the fin whale as opposed to the other whales – which simply isn’t true. 

Postage stamp from
the Faeroe Islands

Fin whales are endangered as 20th Century whaling claimed around 725 000 animals, leaving only around 40 000. Since the moratorium numbers have risen back to around 100 000, but their numbers may never fully recover. Several countries still hunt them. 

There are at least 2 subspecies of fin whales, and possibly a third or even a fourth, which haven’t been named yet. They do mix with each other, but only very infrequently. There is also evidence of hybrid crosses with blue whales. The differences and similarities between fin whales and blue whales have been compared to those between humans and gorillas, yet there is a lot of evidence for hybrid individuals existing. 

Asymmetrical colouring on the right mandible

A curious and unexplained feature is the asymmetry of their faces. Fin whales are generally dark brownish-grey on their backs, and white on their bellies, with some variation between Atlantic and Pacific populations, but on the right mandible or lower jaw there is a light, white patch of colour that isn't there on the left side and no one knows why. This asymmetry is often seen in omura’s whales, and also occasionally in minkes, but it is always there in the fins and it remains unexplained.

Fin whales live to be around 100 years old, but specimens have been found much older, up to 140. They like to sing and they have the lowest frequency voices of any animal on Earth. Their songs can be heard from hundreds of miles away. When they were first detected, scientists thought the recording equipment was broken, or else they were coming from some experimental technology used in Soviet submarines. The amount and volume of noise in the oceans now is playing havoc with many whale populations. 

Whale watching tour.

Ship strike

The noise of the big engines of all the worlds shipping – commercial, military, luxury and others, and especially the sonic blasters being used in the search for oil sources below the surface, have turned the marine world into a spectacularly noisy place, and if you use sound as your primary sense and your means for navigating, it can be disastrous. A cetologist once described it to me as being akin to trying to live out your life in a perpetual disco, with strobe lights flashing continuously, all day and all night. Whale populations are responding by moving away from shipping channels, but this also means away from food supplies, so numbers are not recovering as quickly as may be hoped.  Predation by orcas, ship strike and entanglement are major causes of death for these and other whales and is another reason why the population recovery is so slow. But on the positive side, most countries now respect the moratorium and would never consider returning to whaling. The populations are recovering, albeit slowly, and we are learning more about whales all the time. I wonder what names we might come up with for the fin whale.