Longest single journey by a mammal

Humpback whales (Megaptera novaeangliae) are some of the most far-ranging animals, regularly making epic journeys across the oceans in search of food or a mate, routinely covering distances of some 8,000 km (5,000 mi) during their annual migration between the tropical breeding grounds and cooler polar feeding grounds. However, one exceptional adult male humpback has been found to have embarked on a journey of at least 13,046 km (8,106 mi) from breeding grounds in the Gulf of Tribugá on the Pacific coast of Colombia where it was seen by researchers on 13 August 2017 to breeding grounds off the Tanzanian archipelago of Zanzibar, East Africa, in the Indian Ocean on 22 August 2022. The longest documented single journey ever undertaken by a mammal was discussed in the journal Royal Society Open Science on 11 December 2024.

The male humpback was identified using photo-identification and adapted facial-recognition software which was able to match the unique shape and markings of its tail flukes. This technology is part of a citizen-science project known as Happywhale.com which collates photographs of whales from both scientists, whale watchers and members of the public who submit their photographs to the database to track whales’ movements around the world.

In reality, this whale probably covered much farther than 13,046 km overall. This was calculated based on a measurement known as “great circle distance”, which is essentially the shortest possible route between two points on a sphere (i.e., its two sightings off Colombia and Zanzibar). Marine biologists involved with the research believe it’s highly likely that en route between the two breeding grounds this whale would also have travelled south to Antarctic waters to feed. It is rare for humpbacks to move between two different ocean basins and this one passed through three: the Pacific, Atlantic and Indian.

The 2024 paper was a collaboration between scientists from the Tanzania Cetaceans Program (Tanzania), Bazaruto Center for Scientific Studies (Mozambique), Macuáticos Colombia Foundation, Jardín Botánico del Pacífico Mecana, Madre Agua Colombia (all Colombia), DMAD-Marine Mammals Research Association (Türkiye), Southern Cross University (Australia), Happywhale.com and the University of Washington (both USA).

This blows the previous longest journey logged by a humpback whale out of the water. This was for a female that was sighted off Brazil in August 1999 and then spotted two years later near Madagascar in the Indian Ocean – a distance of at least 9,800 km (6,089 mi) – as discussed in a paper published in Biology Letters on 23 April 2011.