LONDON (AP) - It wasn’t love. It could have been adventure. Or maybe she just got lost.
It remains a mystery why a female humpback whale swam thousands of miles from the reefs of Brazil to the African island of Madagascar, which researchers believe is the longest single trip ever undertaken by a mammal _ humans excluded.
While humpbacks normally migrate along a north-to-south axis to feed and mate, this one _ affectionately called AHWC No. 1363 _ made the unusual decision to check out a new continent thousands of miles to the east.
Marine ecologist Peter Stevick says it probably wasn’t love that motivated her _ whales meet their partners at breeding sites, so it’s unlikely that this one was following a potential mate.
“It may be that this is an extreme example of exploration,” he said. “Or it could be that the animal got very lost.”
Stevick laid out the details of the whale’s trip on Wednesday in the Royal Society’s Biology Letters, calculating that, at a minimum, the whale must have traveled about 6,200 miles (10,000 kilometers) to get from Brazil to Madagascar, off the coast of east Africa.
“No other mammal has been seen to move between two places that are further apart,” said Stevick, who works at the Maine-based College of the Atlantic. And while he said “the distance alone would make it exceptional no matter where it had gone,” there was an added element of interest.
Humpbacks are careful commuters, taking the same trip from cold waters where they hunt plankton, fish and krill to warm waters where they mingle and mate “year after year after year,” he said. The location of their feeding and breeding spots sometimes varies, but their transoceanic commute doesn’t usually change much.
“That’s almost 90 degrees of longitude _ so a quarter of the way around the globe,” Stevick said. “Not only is this an exception, but it’s a really remarkable exception at that.”
Humpback whales are powerful swimmers, and the 40-ton (36-metric ton) behemoths typically clock up 5,000 miles in their trips from the frosty waters of the North Atlantic and the Antarctic to more temperate areas around the equator. They’re known for their eerie songs _ composed of moans and cries _ which travel huge distances underwater and whose precise function remains a mystery.
They’re also cherished by whale-watchers for their spectacular out-of-the-water jumps, called breaching.
Their numbers have recovered since they were almost hunted to extinction in the mid-20th century. But improvements have been uneven and scientists have been studying the whales and their movements to understand why.
It’s to that end that Stevick and other experts have been trawling the Web for photos taken by tourists and whale-watchers, hoping to help build on a worldwide catalog of humpback whales which can be used to track where they travel.
It was by browsing photo-sharing site Flickr that one of Stevick’s colleagues found a photo of this particular humpback, taken by a Norwegian tourist from a whale-watching vessel off the coast of Madagascar in 2001. The photo had been taken with a film camera and the negative sat undeveloped in a drawer for years. Eventually, it was scanned and posted to the Web, where it was spotted and added to the catalog.