Humpback whale sets record for how far it travelled in search of mate: 13,000km

LONDON – A humpback whale set a record by traversing at least three oceans and more than 13,000km – most likely in search of a mate, according to a new study.

A team of scientists identified the adult male, which swam 13,045km from breeding grounds in Colombia in South America to breeding grounds in Zanzibar in Africa from 2013 to 2022.

The unusual odyssey is the longest recorded distance travelled by the species and is the subject of a study published on Dec 11 in the journal Royal Society Open Science, potentially providing new insights into the migration patterns and behaviours of humpback whales.

The study suggests that mating and environmental factors could have influenced the whale’s long voyage.

According to the study, scientists looked at pictures on Happywhale, an online platform that collects photos of whale flukes – or tails – from scientists and members of the public from around the world.

The platform uses artificial intelligence-powered photo-matching algorithms to help automatically identify the whales in submitted photos. Those matches were confirmed or rejected by data managers, the study said.

The whale was first photographed in July 2013 off the coast of Colombia in the Pacific Ocean, where it was part of a “competitive group” that included seven humpbacks.

That same whale was photographed in 2022 in the south-west Indian Ocean off the coast of Zanzibar – 13,045km from where it was first spotted nine years earlier.

Researchers originally thought there had been some kind of error.

“The immediate reaction was, ‘This is a mistake. One of these photos is out of place,’” said Mr Ted Cheeseman, co-founder of Happywhale and one of the study’s authors.

But it was confirmed to be the same whale. Scientists determined it was a male because the whale was competitively active in the mating pods it travelled with and because of a photo of its genital area, according to the study.

Humpback whales have one of the longest migration patterns of any mammal on the planet, according to Noaa Fisheries, with some populations travelling 8,000km from tropical breeding grounds to colder waters in search of food.

What was remarkable about this whale’s journey was that it involved crossing multiple populations between where it started in South America to where it was most recently photographed in Africa, Mr Cheeseman said. And it embarked on the journey as an adult.

“By the time humpback whales are adults, they’re usually in very fixed, consistent patterns,” he said. “This whale did something totally different.”

Why it did what it did

Researchers have previously identified humpback whales that swam astray of typical migration patterns. But the whale identified in the Royal Society Open Science study is unique, in part for just how far it travelled, setting a record for the longest documented great-circle distance – the shortest path between two points.

Scientists cannot be sure why exactly the whale followed the path it did. The study suggests that climate change and other environmental changes may have played a role, as well as the search for food.

The paper also considers that population growth could lead to increased competition among males, sending animals farther afield to search for food and mates.

In one sense, the research highlights just one individual whale moving across populations, which has been studied before, said Dr Olaf Meynecke, a marine scientist and manager of the Whales and Climate research programme at Griffith University in Australia who was not associated with the study.

“It would be more powerful to have multiple individuals, and not just looking at one individual whale,” he said.

It is the bigger picture of having larger data sets that Dr Meynecke said he finds more interesting, particularly with facial and fluke recognition technology.

“It shows how advanced our data collection is,” he said. “This automated fluke recognition really helps us to find individuals, and then understand their movement patterns a lot better.”

Understanding the behaviour and movement patterns for any species is illuminating, but particularly with humpback whales, whose populations have rebounded in recent decades after being decimated by commercial whaling. But that comeback is happening amid other oceanic changes, Mr Cheeseman added. “That sets up for surprises.”

Ultimately, the study also helps highlight the need to care about and protect the oceans.

“There is no humpback whale in the world that lives only within one nation’s waters,” Mr Cheeseman said.

“These are international waters and multinational waters, and we need to, as researchers and as a community who care about the oceans, we need to manage them accordingly. We need to protect them as international and connected waters.” NYTIMES