Humpback Whale Sets 15,100km Sighting Record Between Brazil and Australia

9 articles · Updated · The Guardian · May 20

A humpback first photographed off Brazil in 2003 was identified again in Hervey Bay in September 2025, creating what researchers say is the longest documented distance between sightings of one humpback.
19,283 fluke photos from 1984 to 2025 and Happywhale’s AI matching system linked the whale by its unique tail markings after a 22-year gap between sightings.
The study also found a second whale moved the other way—from eastern Australia to Brazil—over about 14,200km, making the pair the first recorded two-way exchange between the populations.
Researchers said the crossings appear extremely rare—just 0.01% of identified whales—but they suggest whale conservation must be coordinated across borders as climate change reshapes migration and feeding grounds.

Are these record-breaking whale journeys a sign of incredible adaptability or a desperate response to a changing climate?

How is AI revealing whale behaviors that could force us to redraw international conservation boundaries?

If male whales roam between oceans but females stay loyal, what does 'population' truly mean for them?