On 12 October 2009 a pelagic birdwatching trip off San Francisco, California, USA was treated to a prized sighting of a Short-tailed Albatross Phoebastria albatrus. But at the time, they didn’t know just how special the bird was. According to Japan’s Ministry of the Environment, a band on the bird's leg and a transmitter taped to the bird's back indicated that it was one of the 15 chicks that had been translocated from Torishima to Mukojima Island in Japan, and hand-reared by scientists seeking to establish a new breeding colony on this formerly occupied island. Click here for an earlier ACAP news item on the Japanese translocation efforts.
A translocated Short-tailed Albatross, in juvenile plumage, fledged from Japan's Mukojima Island seen off the coast of California, USA on 12 October 2009. Photograph by Alvaro Jaramillo, San Francisco Bay Bird Observatory.
In February this year, the 15 albatross chicks were moved to Mukojima Island, part of the Ogasawara Islands some 350 kilometres away from their original nesting site on Torishima. After a few months of hand-feeding, all of them successfully had left the hopeful breeding colony by 25 May.
Researchers had attached satellite transmitters to seven of the chicks prior to them leaving to follow their migration routes, and when the individual was observed off the coast of California in October, its satellite tag was still intact and relaying its position to Japanese and USA scientists.
The bird was tracked to the southern tip of the Kamchatka Peninsula in early July. From there, it crossed the Pacific Ocean toward the Gulf of Alaska via the Aleutian Islands, and then flew along the western coast of Canada down to California, researchers said.
Movements of the translocated Short-tailed Albatross photographed in Californian waters. Courtesy of Rob Suryan and the North Pacific Research Board.
Of the seven banded birds, two were located in the Bering Sea, while one was confirmed to be in the Gulf of Alaska. However, the remaining three have not yet been spotted at sea. The transmitters are attached in such a way that as the birds moult their back feathers, the devices are shed. It is possible that some of the devices had been shed in this way or had malfunctioned prematurely.
Short-tailed Albatrosses that fledge from Torishima and the Senkaku Islands migrate to the Bering Sea, Aleutian Islands or to the coast of Alaska in summer, before coming back to their breeding colony after several years. Early indications suggest that the translocated chicks behave in the same manner, although it is not yet known to which colony site they will return. Scientists are hopeful that they will return to Mukojima, the site from which they fledged, where they can jump-start the formation of a new colony away from the volcanic threats that exist at the colony from which they hatched on Torishima.
The Short-tailed Albatross was added to the list of species listed within ACAP earlier this year, along with the two other North Pacific albatrosses, the Laysan P. immutabilis and Black-footed P. nigripes. Click here for the ACAP Species Assessment for the Short-tailed Albatross.
For more information on the translocation programme and satellite-tracking the birds go to http://www.nprb.org/.
Lindsay Young, North Pacific News Correspondent, 18 November 2009, updated 20 November 2009