Two humpback whales have traveled record distances between Australia and Brazil. These marine mammals, known for their long migrations, have this time broken all records by swimming in opposite directions. Their exceptional journey challenges what was previously believed about the isolation of whale populations.
Scientists identified these two individuals thanks to the unique patterns on their tails, comparable to fingerprints. By analyzing over 19,000 photos collected over four decades by research teams and citizen scientists, they found the same whales on breeding grounds in eastern Australia and Brazil. A recognition software helped match the images, confirming these crossings.
The distance traveled by one of them reached 9,320 miles (15,000 kilometers). This record surpasses that of a whale that swam from Colombia to Zanzibar. These impressive figures show the scale of possible movements for these ocean giants.
Usually, humpback whales follow migratory routes learned from their mothers, with predictable patterns between feeding and breeding areas. Finding two individuals linking such distant breeding sites is therefore exceptional.
The reasons for these journeys remain unclear. Perhaps these whales encountered other individuals on shared feeding grounds and took a detour instead of returning home. Since the photos only show the start and end of the journey, the exact route remains unknown.
These record crossings also have implications for conservation. Climate change is altering the distribution of krill, the whales' main food source. The tracking methods will make it possible to monitor their future movements in response to environmental changes.
Geographic location and photographic documentation of exchanges between humpback whales from eastern Australia (breeding population E1 (BSE1)) and Brazil (breeding population A (BSA)). Humpback whale migrations
Humpback whales are famous for their long seasonal migrations. Each year, they move between feeding areas rich in krill and small fish, located in cold polar waters, and breeding areas in warm tropical waters. This annual cycle can cover thousands of miles.
The young follow their mother on their first voyage and memorize the route. This creates distinct populations with their own migratory routes. Humpback whales in the southern hemisphere, for example, often go to Antarctica to feed and then head back to the coasts of Australia or Brazil to breed.
However, individuals may sometimes stray or explore new routes. Distance records, like this one, show that their navigational ability is great.