Credit: iStockphoto
PARIS: A humpback whale has broken the world record for travel by any mammal, swimming at least 9,800 kilometres from the Atlantic to the Indian Ocean in search of a mate.
The female humpback was first photographed among a group of whales at a breeding ground on Abrolhos Bank, off Brazil's southeastern coast, on 7 August 1999.
By sheer chance, it was photographed more than two years later, on 21 September 2001 by a commercial whale-watching tour at a breeding ground near the Ile Sainte Marie off the eastern coast of Madagascar.
Distinctive tail and spots
The whale was identified thanks to the distinctive shape of its tail and a pattern of spots on it.
"It is the longest documented movement by a mammal, about 400 km longer than the longest seasonal migration that has been reported," according to the research, headed by Peter Stevick of the College of the Atlantic in Bar Harbor, Maine.
The trip is not just remarkable for the distance the whale covered, said Stevick. It also raises exciting questions about the breeding habits of humpbacks (Megaptera novaeangliae), a species of which relatively little is known.
Not just north-south migrations
Until now, it was thought that only males, rather than females, would be likely to wander such extreme distances in quest of a partner.
Humpbacks are known to be long-distance swimmers, but until now their migration patterns were thought to be between northern and southerly latitudes. For instance, a whale might head to feeding area in a far southern latitude in the Atlantic, and then return to a tropical latitude in the Atlantic in order to breed.
But this discovery suggests that humpbacks may also have a migratory pattern that straddles longitudes, not latitudes. In other words, they could swim east-west to breed.
