Searching for the loneliest whale in the world

Somewhere in the North Pacific there’s a whale singing at a much higher pitch than other whales. This has made us believe that no other whales can hear it and for a decade it has been called “the loneliest whale in the world” believed to struggle finding a partner. But recently it has been questioned how unique it is for a whale to sing at a higher pitch and how lonely it really is.

In the late 1980s the US Navy started sharing their recordings from hydrophone arrays with whale researchers. The recordings were undertaken part of the US Navy’s search for submarines in the North Pacific but happened to pick up whale song too. Male whales sing during mating season in order to localise a partner. Fin and blue whales sing at a low pitch around 17-20 Hz which is well below the limits of human hearing. A low pitch is ideal for sound that needs to travel extremely long distances underwater and whale songs need to travel hundreds and sometime thousands of miles from the source. In 1989 whale researcher William Watkins noticed a sound at a much higher pitch of 52 Hz. The researchers started trying to track the movements of this unique whale that soon became known as the 52 Hz whale. For 15 years researchers managed to record the so-called 52 Hz whale. Generally it is very difficult for researchers to track an animal by the sound only but the high pitch made it easier to recognise the 52 Hz whale compared to other whales singing at the same frequency. In 2004 a scientific paper about the whale’s unique vocal properties based on recordings and analyses by William Watkins was published in the journal Deep Sea Research. In the paper they described their findings and discussed the fact that despite a lot of recording and monitoring they hadn’t found any other sound identical to this. The paper was picked up by the popular press and the 52 Hz whale was soon nicknamed “the loneliest whale in the world”. In the popular press a heart-breaking story was made up saying that there’s a whale that travels across the Pacific Ocean crying out for a partner unable to find one as it sings at a pitch other whales don’t necessarily are be able to hear. However that might not be the case. Some research has shown that there are groups of whales in certain regions that all sing at the same special pitch. And we shouldn’t assume that other whales can’t hear the 52 Hz whale and other pitches just because they sing at a lower pitch themselves. Perhaps the 52 Hz whale sings this way to be better heard… Or the 52 Hz whale may be part of a group but sometimes wanders off on its own. But we don’t know for sure and until we’ve found out, the 52 Hz whale remains a great mystery in the animal kingdom. First of all, no-one has ever seen the 52 Hz whale and we don’t know whether it’s still alive because the last original recordings took place in 2004. We don’t know for sure whether the whale is male or female and we don’t know what species it is. Many think it is a hybrid and it has similar migratory patterns as blue whales and is therefore believed to be at least part blue whale. Interestingly, the findings of the recordings of the 52 Hz whale presented in the scientific paper by William Watkins also showed that it has gradually deepening to 47 Hz over the years.

William Watkins died the same year as his paper on the 52 Hz whale was published (2004) and in the years to come no researcher was particularly interested in tracking the 52 Hz whale. Only in 2010 a new research team took over the search for the 52 Hz whale after having recorded whale song with the same pattern as Watkins’ recordings. However, this new team, lead by researcher John Hildebrand, used several recording sensors widely separated from each other and soon discovered that this unusually high pitch song was recorded by several sensors at the same time suggesting there is at least one more whale (or other animal!) singing at around 50 Hz.

In autumn 2015 an expedition including a film team will start the enormous challenge of finding the correct whale and video recording it. Although the 52 Hz whale may be a giant the Pacific Ocean is enormous. Chances of being successful seem poor as low frequency sound can travel thousands of miles making it almost impossible to identify the location of the 52 Hz whale. Not knowing where to start, the expedition will be like looking for a needle in the world’s largest haystack.

Sources:
Watkins, WA., Daher, MA., George, JE. & Rodriguez, D. Twelve years of tracking 52-Hz whale calls from a unique source in the North Pacific. Deep Sea Research. 2004(51);12:1889-1901 http://www.sciencedirect.com/science/article/pii/S0967063704001682

BBC Earth 15/04/15
The world’s loneliest whale may not be alone after all
http://www.bbc.com/earth/story/20150415-the-loneliest-whale-in-the-world

Kickstarter. Help Find the Lonely Whale.
https://www.kickstarter.com/projects/lonelywhale/help-us-find-lonely-whale