May 31, 2018

MAMMAL NAMES | Super-Powered Cetaceans:

The Other Marvellous Names, Attributes & Abilities of Ireland's Baleen Whales

The baleen whales in Ireland's seas have many more super powers besides super size, from which many of their titles derive

Over the last few months, it has become abundantly clear to us just how incredibly large the baleen whales in Ireland’s seas are. But super size is not the only super power they can claim. This month we will see that collectively these mighty marine marvels possess everything from super sound to super speed, and even super age, and these powers are reflected in their names and the titles they can claim. A voyage to the deep in Ireland’s seas, then, would be breath-taking in more ways than one, populated as these waters are with super-powered cetaceans.

We can begin by taking a look at what is one of the most fascinating super powers exhibited by the baleen whales in Irish waters – super sound. A few months ago, we saw that the humpback whale pips the blue whale in some aspects of super size, and this also appears to be true when it comes to their sound-based super powers.

The low-frequency moans of the blue whale can travel astonishing distances through the sea – over 150 kilometres, in fact, which is equal to the distance between the cities of Cork and Galway, as the crow flies. However, the humpback produces not only calls that can travel similar distances, but that are far more complex. Indeed, they possess the most complex repertoire of sounds in the whole whale order, which range from high-frequency clicks, chirps, and whistles, to low-frequency snores and moans.

Some of the baleen whales in Ireland's seas can communicate using super sound over distances equal to that between Cork City and Galway City

The males are the ones who put this incredible voice to most use, though, producing complex ‘songs’ that they sing on breeding grounds which are thought to have a function in attracting females. These songs are a true expression of culture, varying as they do from one local area to the next, and they also change from year to year. And while human performers like Bruce Springsteen may be lauded for the length of their performances, his shows sometimes exceeding four hours in length, in humpback society he would be considered a mere lightweight, with males singing songs that last about 10 minutes on a constant loop that can continue for over 24 hours. When it comes to sound, then, it is the humpback whale that can truly claim the title of ‘the Boss’, and humpbacks have been described as ‘inveterate composers’.

And recently it has emerged that the humpback is not the only baleen whale in Irish waters that can produce such marvellous underwater vocal masterpieces, as the bowhead whale also sings songs of wondrous complexity. In fact, bowheads appear to be masters of improvisation, regularly creating new songs. As one expert has put it: “If humpback whale song is like classical music, bowheads’ are jazz. The sound is more free-form.” However, it is as yet unknown if, like the humpbacks, it is only the bowhead males who engage in singing.

Being a creature of such great musicality, it would seem fitting that this whale would have as musical an English name as ‘bowhead’. But this name does not, of course, refer to the musical abilities of this mighty cetacean, but rather to the shape of its head, which is remarkably bow-shaped and also massive, accounting for up to 40 per cent of its total body length.

It is easy to appreciate from this image how the bowhead got its name

So, the bowhead whale and the humpback whale appear to be the masters of super sound. However, when it comes to the humpbacks at least, they fall short in terms of a super power possessed by some of the other baleen whales in Irish waters – super speed.

Previously, we have seen that the humpback whale is a member of the Balaenopteridae family, along with four other baleen whales in Irish seas – the northern minke whale, sei whale, fin whale, and blue whale. However, whereas these latter four all belong to the genus Balaenoptera, the humpback belongs, as we saw before, to another genus, Megaptera. And one of the ways in which the humpback differs from its fellow balaenopterids, aside from having longer pectoral fins and fewer throat grooves, is that it is more robustly built. The members of Balaenoptera are slimmer and torpedo-shaped, so it should be no surprise that the holder of the title ‘fastest baleen whale’ should hail from their ranks.

However, just which of them is the true champion of super speed is unclear. Some sources state that the fin whale is the fastest , and this is even reflected in one of the names bestowed on it – ‘greyhound of the sea’. However, others hold that it is the sei whale that is the fastest. However, claims that the sei whale can reach speeds of up to 55 km/hour appear to be untrue.

The slim, torpedo-shaped fin whale has been called the 'greyhound of the sea' due to its great swimming speed

A 1999 study still cited by very recent academic papers looked at various studies of whale speed, and one from 1957 recorded the maximum speed of the fin whale as equating to just under 25 km/hour, although later ones recorded much greater maximum speeds, of over 37 km/hour. In contrast, the same 1957 study recorded the maximum speed of the sei whale as equating to just over 48 km/hour, while later studies recorded far lower maximum speeds, of just under 30 km/hour.

If we were to take the highest recorded maximum speeds of each whale as a true reflection of the actual speed attained by them, we would have to accord the sei whale the title of ‘fastest baleen whale’ in the sea. However, there is such a large discrepancy between different studies that the fin whale too could claim to deserve this title.

What is not in doubt, though, is that these whales certainly possess super speed. Even their lower maximum speed estimates far exceed any speed achieved by a human, the maximum speed reached by the Olympic swimming great Michael Phelps, for example, being less than 10 km/hour.

The greatest name in the history of Olympic swimming, Michael Phelps, would be absolutely battered in a race with the sei whale or fin whale, contenders for the title of 'fastest baleen whale'

And their higher maximum speed estimates compare quite well against the maximum speeds of the very fastest whales in the sea, which all belong to the toothed whale side of the order. The Dall’s porpoise of the North Pacific appears to be the very fastest, with a maximum speed of just over 55 km/hour. However, Ireland’s waters can also claim some of the speediest forms, home as they are to the killer whale, which has a maximum speed of 45–55 km/hour, and the common dolphin which reaches maximums of 45–50 km/hour. Considering, though, just how much larger than these toothed whales the baleen whales are, the highest speeds achieved by them are truly impressive, and even the greatest of them, the blue whale, can surge through the sea at speeds as astonishingly high as 30–37 km/hour.

It seems the mighty blue whale, then, may not be too far off matching the fastest baleen whales. But while it may be able to give the sei whale and fin whale a run for their money in terms of super speed, when it comes to the last super power we must meet, super age, there is another whale in Ireland’s seas that absolutely leaves it in its wake.

The blue whale can live a very long life, well capable of reaching 80–90 years of age in the wild, while one dating technique estimated the oldest individual to have reached a very impressive 110 years old. However, amazingly, its fellow baleen whale, the bowhead whale, can live more than twice as long. From the dating of stone harpoon tips found in their blubber, as well as analyses of their eye tissue, it is now known that bowhead whales can live for over 200 years, while a DNA study published in December 2019 concluded that their maximum lifespan was a mind-boggling 268 years. This confers on them the venerable title of ‘oldest mammal on Earth’.

And just to put the incredible age of these marine Methuselahs in perspective, this means that the oldest bowheads still sailing the seas in our modern world were on the cusp of becoming centenarians at the time the Great Famine began in Ireland back in 1845. And by the time Ireland’s revolutionaries rebelled against their British rulers in the 1916 Rising over a century ago, many of these same great whales would have been well past their 150th birthdays!

At the time of the 1916 Rising, centred on the General Post Office (G.P.O.) in Dublin (above), some bowhead whales still alive today would have been well over 150 years old, and they are the undisputed holders of the title 'oldest mammal on Earth'

What a mind-blowing fact that is, and it is a very fitting one to round off our exploration of the amazing super powers of the baleen whales in Ireland’s waters. These incredible hulks can zip through the sea like a flash, truly unstoppable juggernauts, while some can not only cast their voices like a banshee but sing as sweetly as a robin. And when it comes to longevity, these fantastic beasts can claim a member that is truly a wonder. Together, then, these super-powered cetaceans are a very gifted bunch – a league of extraordinary giants.