The fin whale is the second largest animal on the planet after the blue whale. As for all the whales, females are larger than males and individuals in the southern hemisphere are also bigger and longer than the ones in the northern hemisphere. Their backs are black, their flanks are very dark and the belly is white. They have the specificity to have a white right mandible while the left one is black.

© photo Anne Collet

We still find them in all the oceans, but their numbers have fallen in the last century: for the moment the total population is estimated at some 100 000 individuals, while they were probably more than 500 000 before the industrial commercial hunting started.

Most of them migrate each year, in autumn to the equator, to calf, then in spring to the cold higher latitudes to feed. They reach sexual maturity between 6 and 12 years, the gestation period last for 12 months, then the calf is weaned at about 5-6 months, but a female has not more than one calf every 3 to 5 years as she is resting between the lay-downs*.

The fin whales feed on krill or small fishes. In general they dive between 50 and 250 m for 10 to 20 minutes.

* Did you know?

To be pregnant, baby and children are all terms reserved for the human species in theory. For animals we talk about gestation, calves and juveniles.

© photo Anne Collet

Unlike other whales, the fin whales do not fluke, i.e. their caudal fin goes out of the surface, when they dive although some exceptions do exist (as the individual on the left). Their travelling speed is usually of 6-8 km/h, but if they are disturbed they can attain speed of 40 km/h.

In order to not confuse a fin whale with other close species:
- blue whales are bigger (up to 30 m long), lighter in colour and spotted of a grey-blue colour and their dorsal fin are twice smaller (about 30 cm)
- sei whales are smaller (16-18 m) and when they surface their head and fin appear at the same time while the dorsal fin of fin whales comes out later, i.e. a few seconds after the blow.

CIRCE Newsletter n° 1 made by Anne Collet & Philippe Verborgh

<< previous page                next page >>