For a few humpback whales, the entire world is their oyster. New research published Wednesday reveals that two of these whales have essentially traded one part of the ocean for another one — on the other side of the planet.
It was already known that some of these whales will sometimes shift their breeding and mating grounds for others thousands of miles away. But the whales documented in today’s study traded their preferred ocean home after living in their previous zone for many years. One of them moved from Australia to waters near Brazil, while the other immigrated in the opposite direction: from Brazil to Australia.
The distances traveled by the whales were 8,800 miles or more — roughly equal to the distance between Sydney and London. They’re the longest distances ever documented between sightings of the same individual humpback whales.
“Finding whales that have switched between populations on opposite sides of the planet is extraordinary,” the Pacific Whale Foundation said in a news release.
The Importance of Citizen Scientists
The ability to track these whales across the globe was only possible thanks to collaboration between various scientific institutions in Brazil, Australia, Ecuador, and the United States.
But even this global coordination of researchers couldn’t have made this discovery without the help of citizen scientists.
The whales are identified primarily through their flukes, each of which has a unique pattern just like a fingerprint. Researchers relied on the photographs of flukes uploaded to Happywhale, a global platform for uploading images of whales used by both professional researchers and citizen scientists. The new study looked at nearly 20,000 high-quality fluke photographs collected between 1984 and 2025 from eastern Australia and Latin America.
Scientists then ran those photographs through an automated image-recognition algorithm. Then, they independently verified every potential match by eye. The evidence was clear: two humpback whales that had been photographed in both regions.
“This kind of research highlights the value of citizen science,” said Cristina Castro, an Ecuadorian researcher with the Pacific Whale Foundation. “Every photo contributes to our understanding of whale biology and, in this case, helped uncover one of the most extreme movements ever recorded.”
Broader Implications
The knowledge that humpbacks travel farther than previously known is itself a powerful reminder of how much we can still learn by studying nature. However, there are several significant implications of the new findings.
One of them is that humpbacks could be more resilient to the effects of climate change. Southern whale populations are at risk from the impact of global warming on Antarctic prey, a vital food source. If these globe-trotting whales are able to successfully breed in their new regions, it could allow the species to adapt to oceans that are rapidly changing due to greenhouse gases.
According to the Pacific Whale Foundation, the findings also support what scientists call the “Southern Ocean Exchange” hypothesis. That’s the idea that humpback whales from different breeding populations occasionally meet on shared Antarctic feeding grounds, and that some individuals then follow a different migration path home, ending up, perhaps for the rest of their lives, in an entirely new breeding region.
“Climate-driven changes to the Southern Ocean, including shifts in sea ice and the distribution of Antarctic krill (the whale’s main prey), may be making such crossings more likely over time,” according to the nonprofit.
Humpback whales were once hunted nearly to extinction, and have only made a comeback thanks to strict regulations against whaling. Scientific research shows that these animals can still surprise us. In 2022, whale researchers revealed that humpbacks share their songs across oceans, gradually creating new songs each year as the global population learns the old melody.
“Half the globe is now vocally connected for whales,” Ellen Garland, a marine biologist in Scotland, told The New York Times. “And that’s insane.”
