Sunday 17 October 2010

Humpback migration revelation


The record of a humpback whale's remarkable movement between non-adjacent breeding areas has been published online in the Royal Society's peer-reviewed independent journal, Biology Letters.

First photographed on the Abrolhos Bank, off the coast of Brazil in August 1999 and identified as a female from a skin sample collected by scientists, the whale's underside-fluke image was entered into the College of the Atlantic's Antarctic Humpback Whale Catalogue (AHWC) as whale number 1363.

Some 25 months later, in September 2001, a tourist took a series of images of a humpback whale from a commercial whale watching vessel off Madagascar.

That might have been the end of these two unrelated photographic events. But in 2009, the Madagascar images were posted on the internet. There it was seen by a College of the Atlantic research associate in Maine, USA. Although none of the photographs was a perfect, whole-fluke image, the pattern was sufficiently distinctive to enable it to be matched with the catalogued fluke AHWC No. 1363.

While it is not known how this whale made its way from a breeding area at around 38 degrees 43’ W to another at 49 degrees 50E over a two year period, even a journey by the most direct route would have covered in excess of 5,300 nautical miles (9,800 kilometres). This is not only the longest documented movement by an individual humpback whale; it is the longest for any mammal (other than humans).It is also interesting that this individual was a female because previous research suggests that males are more likely to undertake long-distance movements between breeding areas.

The publication serves to demonstrate a number of other things including the importance of continued photo-identification fluke capture-recapture programs and the potential for commercial whale watching operations and private individuals to contribute to cetacean research.

But perhaps the most poignant lesson to be learned is that if AHWC No. 1363 had been 'sampled' as part of a lethal scientific whaling program, instead of having her photograph taken and a skin sample collected, this important information about humpback distribution would not have been discovered. In fact, this whale would not even have undertaken her remarkable journey. And make no mistake, southern hemisphere humpback whales are still on the agenda for Japan's current Antarctic 'scientific whaling' program (JARPA II).

[The article "A quarter of a world away: female humpback whale moves 10,000 km between breeding areas" can be accessed at the Royal Society website at http://rsbl.royalsocietypublishing.org]



AWCS

Dedicated to

cetacean

conservation,

education and

research