Humpback Whale Makes Record-Breaking 8,000-Mile Migration Across Three Oceans, but the Reason Is Still a Mystery

An ambitious humpback whale is making waves in the marine biology community after researchers discovered he undertook an incredible 8,106-mile swim across the globe, likely to be the longest distance traveled for the species on record.

This odyssey was “truly impressive and unusual, even for this highly migratory species,” Ekaterina Kalashnikova, a whale researcher at the Bazaruto Center for Scientific Studies and lead author of a study published Wednesday in Royal Society Open Science that tracked the whale’s movements, tells Helen Briggs of the BBC.

Humpback whales are by no means sedentary. According to the study, they “undertake one of the longest known seasonal migrations of all mammals.” However, their migration routes tend to go “between latitudes,” traversing north and south to seek out feeding grounds in colder climates and breeding grounds near the tropics. Rarely do groups of humpback whales go from east to west, preventing them from encroaching on other whales’ territories.

That made it all the more surprising when Kalashnikova and her fellow researchers determined that the same humpback whale was spotted off the Pacific coast of Colombia in 2013 and 2017 before reaching Zanzibar, in the Indian Ocean, in 2022. The whale’s exact route between these endpoints is unknown, but he might have dipped south to Antarctica before tracking back up Africa’s eastern coast, which would extend his route even longer than 8,106 miles.

The discovery was enabled by a citizen science website called Happywhale.com that allows professional biologists and casual whale watchers alike to upload photographs of a whale’s tale, also known as its fluke. Distinct marks, patterns, pigments and scars all contribute to making each whale’s fluke one of a kind. Modified facial recognition software using artificial intelligence matches up distinct features that form a “flukeprint,” as distinct and recognizable as a human fingerprint or face.

“It’s like a five-meter banner of their ID,” Ted Cheeseman, a marine ecologist at Southern Cross University in Australia who founded the site, explains to Petra Stock of the Guardian.

Cheeseman came up with the idea for crowdsourcing fluke images after spending decades leading nature boat tours and watching his passengers snap countless photos. Before software like Happywhale, scientists would spend hours upon hours trying to manually match up pictures of flukes, Christie McMillan, a marine biologist with the Fisheries and Oceans Canada Cetacean Research Program who was not involved with the study, tells Science’s Elizabeth Pennisi.

Now, the site compares each submitted photo with a growing database of more than 900,000 photographs of other whale tails, amounting to some 109,000 individual whales it tracks, Cheeseman explains to Science. It has even enabled other finds, such as identifying a crash in whale populations during the “Blob” heat wave in the North Pacific.

But in the case of this long-distance swimming humpback, Cheeseman first thought his software had gotten something wrong. “This was a very exciting find, the kind of discovery where our first response was that there must be some error," Cheeseman writes in an email to Sascha Pare of Live Science.

While Happywhale tracked this journey, it does not explain why the humpback took such a trip. The study offers several potential explanations.

First, human interference might be knocking whale behavior out of whack. Warmer waters as a result of climate change and krill harvesting could be disturbing traditional humpback feeding grounds, forcing whales to go farther and farther to find food. Alternatively, this journey might be the result of successful global conservation efforts for humpbacks, which are considered endangered in some parts of the world. Humpback population growth could increase competition for food within pods, forcing some individuals to venture out on their own.

The researchers point toward “mating strategies” as a possible key motivation of this wayward whale. Polygyny, a mating system in which males have multiple sexual partners, is “characteristic of humpback whales,” the researchers write. Indeed, in both the Pacific and Indian Oceans, this male was sighted with competition pods of whales, in which one adult female is pursued by a group of males.

But the real explanation is still elusive. If it’s as simple as a male traveling to pursue females, why do female whales also undertake abnormally long odysseys, such as one that traveled from Brazil to Madagascar?

Perhaps these whales were just severely confused, and their lengthy journeys were, one could say, just flukes. But researchers are confident that with new tools like Happywhale, they can determine if these behaviors are indicative of larger global trends facing whales.

“As a world we are way more connected,” Vanessa Pirotta, a whale researcher and author who was not involved with the paper, tells the Guardian, “and that means that the stories that we can tell about whales are more connected globally than ever before.”

Eli Wizevich | | READ MORE

Eli Wizevich is a history correspondent for Smithsonian. He studied history at the University of Chicago and previously wrote for the El Paso Times.