It’s the second-largest animal on Earth, but the mysterious fin whale has long been overlooked by everyone from scientists to photographers, says Philip Hoare. Until now…

By BBC Wildlife Magazine

Published: Tuesday, 21 February 2023 at 12:00 am


What are fin whales?

The fin whale is a type of of baleen whale and the second-longest species of cetacean.

How big are fin whales?

These are truly impressive cetaceans. Surpassed only by blue whales in size, fin whales reach up to 24m in length and weigh up to 70 tonnes.

How fast are fin whales?

In shape they also resemble their blue cousins, with sleek hydrodynamic bodies, signifiers of their speed. So fast is the fin whale – able to reach 37kph – that it has been nicknamed the greyhound of the seas. It can outpace whale-watching boats which, in most oceans, remain its only pursuers.

Fin whale vocalisations

Along with that of the blue whale, a male fin whale’s vocalising is the lowest-frequency sound emitted by any animal. When observers from the US Navy first detected it, they thought that they were hearing Russian submarines. The sound can travel vast distances in water; a fin whale on one side of the Atlantic can be heard by a whale on the other side.

What do fin whales eat?

A fin whale’ diet is usually made up of krill, small schooling fish, and squid. In total fin whales eat around 2 tons of food daily.

Cape Cod is also a good place to observe fin whales’ spectacular feeding technique. Turning on their sides like gigantic salmon, they lunge into a school of sandeels, flashing the white rorqual pleats on their bellies. Such encounters are a perfect way of seeing the whales’ unique asymmetrical markings, a clear diagnostic for the species. The left-hand side of the jaw is dark; the right, pearly white. Some scientists believe that the whales use the white side to startle and concentrate their prey.