Humpback whales set record Australia to Brazil crossings, identified by tail markings

Scientists have identified two humpback whales that completed separate, record-setting swims between Australia and Brazil. The animals were matched using unique tail markings seen at both sites. The locations sit about 9,000 miles, or 14,500 kilometres, apart. The whales travelled in opposite directions, and each journey exceeded earlier known distances for humpbacks.

Representative image

The findings came from a large photo review covering sightings across four decades. Researchers compared more than 19,000 images from research teams and citizen scientists. Software helped match whales by tail colour patterns and jagged edge shapes. The study linked two different whales to breeding areas in eastern Australia and Brazil over time.

Humpback whales record crossing between Australia and Brazil

One whale logged just over 9,300 miles, or 15,000 kilometres, setting a new mark. That distance topped earlier recordholders, including a humpback reported swimming from Colombia to Zanzibar. The research was published Tuesday in the journal Royal Society Open Science. Scientists said the photos only show the start and end points.

Phillip Clapham, a former head of a NOAA whale research program, was not involved. Clapham said, "Its a very rare event, but it is a really wonderful demonstration of just how wide-ranging these animals are,\". Scientists also noted that tracking whales remains hard because they spend most of life underwater.

Humpback whales migration patterns and breeding sites in Australia and Brazil

Humpback whales often travel long distances across large oceans in steady patterns. The routes are usually learned from mothers, scientists said. They feed on krill and small fish in warmer months. They then breed in tropical waters during winter. Even so, movement between different mating sites is not typical.

Because sightings were only at endpoints, the exact path remains unknown. Researchers also cannot yet explain why these two whales switched between breeding regions. Study co-author Stephanie Stack of the Pacific Whale Foundation shared one possible reason in an email. Stack said, \"They may have met other whales on shared feeding grounds and split off instead of returning to where they came from,\".

Humpback whales populations and climate change tracking using whale images

Stack added, \"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,\". Scientists said such long crossings are harder in the Northern Hemisphere. Large continents can block direct ocean travel there, making comparable routes tougher.

Researchers said the record trips underline how far humpbacks can range when conditions allow. The same photo and software methods may also help monitor changes in whale movement. Warming seas could shift where krill live. That may affect where humpbacks go to feed and where they choose to breed.

With inputs from PTI