These are frequently seen off the coast of mainland Portugal throughout the year, and despite not being the biggest mammal in the world (that honour belongs to the Blue Whale), this is a close second. This is the magnificent Fin Whale (Balaenoptera physalus) – and gets its name from an easy-to-spot fin on its back, near its tail. It is massive, sleek and swift, and despite its size, they have a slender and streamlined body that has earned them the nickname of ‘greyhounds of the sea’, reaching speeds up to 40 km/hr. The average male is a colossal 26m long (that’s nearly 85 feet in old money) and weighs 45 tons, with females not far behind, and have an age span of 80 to 90 years. Scientists have noted that they can dive as deep as 339m, with the longest time submerged being 17.3 min. At birth, a newborn calf can weigh up to 1600 kg and has a length of around 6m.

It is doubtful that this is the one Jonah encountered! He was the biblical character who was supposedly saved from drowning when he was swallowed by a ‘great fish’ and lived for three days inside a whale before being vomited out alive. The Fin Whale would certainly fit the bill size-wise - and in case you were wondering, a Fin Whale can't swallow a human - it's physically impossible. While they can have huge mouths, a whale's throat is a lot smaller than you might expect, the size of a human fist. So even if someone was swept into a whale's mouth, they would soon be swept out again.

This creature is a filter feeder that opens its mouth so wide that it can gulp an amount of water larger than the volume of its own body, then strains out small fish and shrimp through baleen plates in their mouths, consuming up to a massive 2,000kg of krill a day. The baleen plates in their mouths are made out of keratin, the same protein that makes up our fingernails and hair. Who would think such a massive creature would eat such small prey?

Fin Whales are brownish to dark or light grey on their backs with white bellies, but the left side of the head is dark grey, while the right side exhibits a complex pattern of contrasting light and dark markings, being dark on the left side of the lower jaw but white on the right-side lower jaw, and the reverse on the tongue. The difference in colouration between each side of the body is called ‘asymmetrical pigmentation’ and some scientists believe this unusual characteristic may have something to do with hunting strategies, although nothing is certain.

Credits: envato elements; Author: SteveAllenPhoto999;

The International Whaling Commission (IWC) issued a moratorium on commercial hunting of this whale, although Iceland and Japan have resumed hunting. The species is also hunted by Greenlanders under the IWC's Aboriginal Subsistence Whaling provisions. Global population estimates range from less than 100,000 to roughly 119,000.

Even though fairly shy and reserved when it comes to showing off their unique tail flukes and acrobatic breaching skills, fin whales are often very friendly with boats.

Despite their ease in spotting prey, whales have poor three-dimensional vision, with eyes located on either side of their heads- Their only predator is the Killer Whale, who will only go after the juveniles - and of course man.

Whale Mating and Courtship

When it comes time for mating season, many migrate to warmer waters, especially if they inhabit a colder ocean region. Like other mammals, whales have their own special behaviours to court females, and engage in songs, calls, and even caresses. Female whales can sometimes be picky when it comes to who they mate with, and a bit flirty (in modern terms, she would be sleeping around), probably to ensure she got pregnant. She will only give birth once in 1 to 5 years.

Experts say that despite the considerable decrease of deaths since the end of commercial whaling and the fast recovery of their populations, they are still a very vulnerable species, with the impact of climate change once again rearing its head.


Marilyn writes regularly for The Portugal News, and has lived in the Algarve for some years. A dog-lover, she has lived in Ireland, UK, Bermuda and the Isle of Man. 

Marilyn Sheridan