Fin Whale

Fin Whale

Rorqual commun

Balaenoptera physalus


Length

18 to 21 m, up to 27 m in the Southern Hemisphere

Weight

40 to 50 t

sociability

Solitary, in pairs or in groups

Longevity

75 to 100 years (the oldest captured specimen was 110 years old)

Dive time

5 to 15 min, up to 25 min

Observations

Regular in summer in the Gulf and the Estuary

Worldwide distribution

From the Arctic to the Antarctic

Worldwide population

Probably around 100 000

Status

Special Concern



Other names: Finback Whale, Razorback or Common Rorqual




A rapid, powerful and flexible giant

The fin whale is the second longest cetacean in the world, after the blue whale. Nicknamed “greyhound of the seas”, it is definitely the fastest of the great whales. It has been observed in the St. Lawrence that, while some fin whales are loyal to their summer feeding grounds and return every year, others have been observed only once or twice. This species is the object of a substantial whale-watching industry in the Estuary.


You can sponsor a fin whale of the St. Lawrence Estuary


Population, range and habitat:

In the St. Lawrence: The fin whale is a seasonal resident of the Gulf and Estuary from May to November; it comes here to feed. Fin whales gather in regions where plentiful food is assured through oceanographic phenomena such as thermal fronts, specific topography and upwelling zones. One such area of note is the head of the Laurentian Channel, located between Tadoussac and Les Bergeronnes. Aerial surveys carried out by Fisheries and Oceans Canada researchers in 1995 and 1996 estimated the Gulf herd—excluding the Estuary—at 380 head. These surveys did not take diving animals into account.

Migration: Migratory movements and winter ranges are not well known. Fin whales appear to undertake small migrations towards lower latitudes in the North Atlantic for mating purposes. However, they do not form large gatherings.

Worldwide: St. Lawrence fin whales are part of the North Atlantic population. Stocks of this population remain ill defined. What's more, accurate fin whale estimates are hard to determine due to their extensive range and possible confusion with sei whales. Yet, the compilation of estimates suggests that the entire North Atlantic population could be as high as 56 000 head. One study has established genetic distinctions between western North Atlantic, eastern North Atlantic and Mediterranean Sea fin whales. This species is present in all of the planet’s oceans from temperate to polar waters.


Behaviour:

Feeding: The fin whale is a gulp feeder. It has a varied diet that includes planktonic crustaceans and small, schooling fish, like herring and capelin. It occasionally feeds at the surface where it swims in circular or semi-circular patterns, often rolling onto its right side. The fin whale is the only cetacean, and one of the rare vertebrate animals in the world, to bear an asymmetrical colouration on its head. On its right side, the lower jaw, bucal cavity, tongue and throat are all of a lighter colour, bordering on white. Thus, the fin whale may use light and contrast to either scare its prey, causing them to coalesce, or as camouflage. A study carried out on fin whale behaviour, as compared to behaviour of other species without this asymmetrical colouration, did not validate either of these hypotheses. This asymmetry may simply be a fin whale characteristic that does not confer any particular advantage.

At the surface: Fin whales generally take five to ten breaths per sequence. On rare occasions, fin whales breach, falling back on their belly or side with a loud noise. This species does not fluke up its tail as it dives; a rapid bending movement of its flexible body is sufficient for it to point its body towards the depths.

While diving: It shows a marked preference for shallow, coastal, 100 to 200 m deep waters with uneven seafloors. It will dive to either just below the surface to as deep as 230 m. Its dive profiles correspond to diverse daytime or nighttime activities, such as travelling, resting, exploring or feeding.

Social behaviour: Fin whales can be observed alone, in pairs or in temporary groups that vary in size from three to 20 whales at a time. The presence or absence of food, as well as tide cycles, have a marked influence on dispersal and grouping behaviour. A 1994 to 1996 study of fin whale behaviour in the Estuary revealed that they swim in tight formation in a synchronized and dynamic manner through tide rips at high tide. At low tide they tended to be scattered and calm.

Vocal behaviour: Fin whales vocalize at low frequencies, below the 120 Hz range. Their repertoire is dominated by short pulsing sounds at decreasing frequencies from 23 Hz to 18 Hz. These pulses may be either isolated or in sequence. For the most part, sequenced pulses are emitted in winter and may be part of a nuptial display. Higher frequency sounds appear to be used to communicate over short distances. According to one study, very low frequency pulses may also be a form of echolocation.


Reproduction:

Males attain sexual maturity between eight and 12 years of age, females between six and 10. Mating takes place in December and January. Gestation lasts 11 to 12 months. Calving occurs from November to January. Nursing lasts from six to seven months. Newborn calves measure on average 6.4 m and weigh 1.9 t. Females can give birth every three years.


About scientific research:

GREMM administers a catalogue of approximately 100 fin whales photo-identified in the Estuary since 1986. Like a family album, this catalogue, allows researchers to keep track of the lives of individual animals such as Capitaine Crochet, Triangle, Caïman and Zipper, to name but a few. The MICS catalogue comprises some 450 fin whales identified in the Gulf of St. Lawrence since 1980.



Fin whale "Science and conservation" page