A humpback whale swam halfway around the world. His name is Frodo.

A battle-scarred male humpback whale named Frodo has completed the longest- known movement for his species, a new study says.

Between 2017 and 2018, the animal swam nearly 7,000 miles from Saipan, in the Mariana Islands, to Sayulita, Mexico, according to a new study published in Endangered Species Research. A female humpback that swam just over 6,000 miles from Brazil to Madagascar in 2001 held the previous record.

When biologist Nico Ransome delved deeper into the male’s astonishing trans-Pacific journey, she discovered it had also appeared near Russia’s Commander Islands in 2010 and 2013, and that Russian scientists had named him Frodo after the Lord of the Rings character who undertakes an epic quest.

Not only did Frodo set the distance record, he’s also flipped the script on what we think of as a humpback’s typical migration patterns, says study leader Ransome, a biologist at Murdoch University in Perth, Australia, and founder of La Orca de Sayulita, a whale watch and research company.

The vast majority of the estimated 7,500 humpbacks that breed off western Mexico migrate north to Alaska and Canada to feed during the summers. Frodo, on the other hand, circumnavigated the entire North Pacific—and, as Ransome would discover, he’s not alone. (Read about a gray whale that set the record for longest migration of a marine vertebrate.)

“I've been obsessed with whale migration for years,” says Ransome. “To find out that some of them go to Russia—I mean, it's mind-blowing.”

A regular route

A few years ago, Ransome started noticing Russian whales showing up in Mexico. She identifies individual animals via an online whale-identification database called Happywhale, which keeps a log of 30,000 humpbacks’ black-and-white fluke patterns that are as unique as a human’s fingerprint.

"It’s like Facebook for whales,” says study co-author Ted Cheeseman, a biologist at Southern Cross University in Lismore, Australia, who co-founded Happywhale in 2015. Hundreds of scientists and dozens of whale-watching companies use the database, which has a 97 to 99 percent accuracy rate for identifying humpbacks, Cheeseman says.

Study co-author Marie Hill, a biologist at the Cooperative Institute for Marine and Atmospheric Research, shared the photo she took of Frodo in the Marianas in 2017 on Happywhale. She says such “open collaboration is key to understanding how the breeding and feeding grounds are connected, which is critical for the protection and conservation of humpback whales.” (Read how humpback whales may face a major setback due to climate change.)

Frodo’s novel journeys spurred Ransome, Hill, Cheeseman, and their colleagues to dig into Happywhale’s archives to see whether other humpbacks were making trans-Pacific migrations. They found 117 individuals that migrated from Mexico to feeding areas in Russia between 1998 and 2021. Prior to this research, only 11 whales had been sighted in both Russia and Mexico.

People spotted more than one-third of these Russian whales in multiple years in Mexico’s breeding areas. Since 2021, Ransome has documented several more Russian whales in Mexico, including mothers with calves—meaning Frodo’s seemingly odd migration is likely a regular route.

Why go so far?

Whales may be making these lengthy trips to find mates, possibly as “a relic from the whaling industry,” Ransome says.

Numbers of these 50-foot-long marine mammals, hunted for their oil, meat, and baleen, had fallen to an estimated low of 1,200 animals in the entire North Pacific—a heavily whaled region—by the 1960s. The population in the western North Pacific is still endangered, according to NOAA, and Hill’s surveys in the Marianas from 2015 to 2018 determined that these islands are indeed a missing breeding ground for humpbacks.

Traditionally, whales that feed in Russia migrate south to breed in Japan, the Mariana Islands, and the Philippines. 

But with fewer whales around, males may have to roam farther to find a mate—even across the ocean to Mexico, Ransome says. They also fight over females, as evidenced by Frodo’s many scars, she adds. (Read about some of the longest and toughest animal migrations on Earth.)

A different tune

These newly revealed migration routes could also explain why humpbacks have been recorded singing almost daily in the mid-Pacific, between Hawaii and Mexico.

Songs in such an unusual location were considered anomalies until a 2021 survey found the same phenomenon. The recordings support the idea that whales are regularly undertaking huge migrations across the world. (Listen to humpback songs from the South Pacific.)

“These whales are always surprising us,” says Heidi Pearson, a marine biologist at the University of Alaska Southeast who was not affiliated with the research. Frodo’s journey, she says, “helps to solve some of that mystery of how a similar song is heard across the whole North Pacific.”

“It just teaches us that we can never assume too many things,” adds Pearson.

As for Frodo, he hasn’t been spotted since Ransome photographed his fluke in 2018. But she wouldn’t be surprised if he’s still making epic voyages across the largest ocean on Earth.