In an extraordinary discovery, researchers have tracked two humpback whales making separate, unprecedented journeys between Australia and Brazil.
The identification of these majestic creatures was possible due to their unique tail markings, recognized in locations nearly 9,000 miles (approximately 14,500 kilometers) apart.
Traveling in opposite directions, these whales have set a new record for the longest known journeys undertaken by humpbacks.
“This is a remarkable event that highlights the incredible range of these animals,” commented Phillip Clapham, a former lead at NOAA’s whale research program, who was not part of this study.
Humpback whales are renowned for their extensive migrations, traversing vast oceanic expanses in patterns typically passed down from mother to calf.
During the warmer months, they feast on krill and small fish, while the winter sees them returning to tropical waters for breeding.
It’s difficult to track the movements of creatures that spend most of their lives underwater.
In the new study, scientists analyzed over 19,000 whale images taken in the past four decades by research groups and citizen scientists.
Recognition software helped to identify the whales based on their tails’ color patterns and jagged edges.
Researchers pinpointed two different whales at breeding sites in eastern Australia and Brazil over the years, suggesting they had crossed from one place to the other.
One whale traveled just over 9,300 miles (15,000 kilometers), outranking previous recordholders, including a humpback that swam from Colombia to Zanzibar.
The findings were published Tuesday in the journal Royal Society Open Science.
Since the photos only depict the whales at the beginning and end of their journeys, researchers don’t know the exact route they took.
Whales don’t typically travel between mating sites, so it’s not yet clear why these two separately embarked on their journeys.
They may have met other whales on shared feeding grounds and split off instead of returning to where they came from, study co-author Stephanie Stack with the Pacific Whale Foundation said in an email.
“Finding not one but two individuals that have crossed between Australia and Brazil challenges what we thought we knew about how separate these populations really are,” Stack said.
Such odysseys are more difficult for whales in the Northern Hemisphere, where massive continents make traveling across oceans tougher.
Scientists said the record journey shows just how far humpback whales can go.
These methods can also help keep track of them as climate change warms oceans, possibly changing where krill live and where humpbacks might go to feed and breed.
