Two Humpback Whales Cross Between Australia and Brazil

Scientists identified two humpback whales that each swam between breeding sites in eastern Australia and Brazil. The animals were recognized by unique tail markings in photographs taken at locations roughly 9,000 miles apart. The crossings occurred in opposite directions.

One whale covered just over 9,300 miles, exceeding the previous known record set by a humpback that traveled from Colombia to Zanzibar.

Researchers examined more than 19,000 whale images collected over four decades by scientists and citizen observers. Pattern-recognition software matched the whales by the color patterns and jagged edges on their tail flukes. The findings were published Tuesday in the journal Royal Society Open Science. Because the photographs show only the start and end points, the exact routes remain unknown.

Humpback whales normally follow migration routes learned from their mothers, feeding on krill and small fish in cooler months and breeding in tropical waters during winter. Travel between separate breeding populations is uncommon. Phillip Clapham, former head of a NOAA whale research program who was not involved in the study, said the crossings demonstrate how wide-ranging the animals can be.

Study co-author Stephanie Stack of the Pacific Whale Foundation said the records challenge assumptions about how separate the populations are. The same tracking methods may help monitor humpback movements as ocean temperatures rise and krill distributions shift.