Humpback whales caught singing the same song almost 9,000 miles away: ScienceAlert

According to a new study, humpback whales throughout the South Pacific are connected through a shared song.

From the east coast of Australia to French Polynesia to breeding grounds in Ecuador—a total distance of more than 14,000 kilometers (8,700 miles)—researchers have heard humpback sounds (Megaptera novaeangliae) trading the same viral hits.

Male humpback whales are known to sing “complex as jazz” mating songs during breeding season, and each population has slightly different vocal choruses that they combine in unique ways.

These many repeated phrases are known as “themes,” and every whale song has several.

However, every once in a while a breeding population will undergo a song “revolution”, whereby all male-sung themes are replaced by new ones.

It’s not clear why they do this, but previous research has shown that these subtle tweaks can turn into hits.

At the turn of the century, humpback populations on the west coast of Australia were found to share themes with populations on the east coast.

Then, years later, populations breeding near French Polynesia were caught singing the same song themes that started off the east coast of Australia, some 6,000 kilometers (3,730 miles) away.

Now it seems that the songs can spread even more. Researchers have shown that whale songs in French Polynesia can migrate across the Pacific Ocean to South America, another 8,000 kilometers (4,970 miles) east.

Over the course of three years, from 2016 to 2018, the team was able to map a gradual song revolution heard first in French Polynesia and again in South America a few years later.

“This study shows that songs first identified in western populations can be transmitted throughout the South Pacific, supporting the potential for southern hemisphere polar cultural transmission of song and a vocal culture rivaled only by ours,” the researchers said.

It is not yet clear whether whale songs will migrate across the Indian Ocean to return to Australian shores.

But according to The New York TimesPreliminary results off the coast of Brazil and South Africa suggest that a full orbit of the planet may indeed be possible.

The whale song probably evolved beyond recognition until it returned to the original breeding population. With one rotation of the planet, it is possible for whales to open a completely new path.

“The study of humpback whale song culture not only parallels the song characteristics of songbirds, but also sheds light on fundamental mechanisms of social learning and cultural evolution in animals, from fish to other cetacean species to humans,” the authors write.

So far, experts aren’t sure how these songs are shared between neighboring whale populations, but they have a leading hypothesis.

While we don’t really know where the humpbacks in French Polynesia typically spend their summer months foraging, if they are feeding in a similar location to Ecuador’s whale populations, then it is possible that they share tunes as they cross or migrate across the Pacific.

Apparently, male whales don’t sing only during the winter breeding season. Ample evidence suggests that they train in the summer as well. And these tunes can be catchy enough to attract the attention of another population.

If so, then the researchers think that whale songs may have gradually spread around the world. First, a song revolution begins in one population, and then in the summer, that population migrates to forage, passing it on to neighboring populations. Etc. Etc.

The researchers hypothesize that the eastward trend is due to differences in population size, with songs shifting from large groups to smaller groups.

To test this theory, it would be interesting to see if songs produced in large western Australian populations also move in the other direction.

Since the late 1990s, researchers in and around Australia have been accumulating evidence that whale songs can morph and migrate within and between populations.

It took decades, but scientists around the world are now listening.

It won’t be long until we know how far humpback songs can travel.

The study was published Royal Society Open Science.

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