Around the World in 46 Days

Irby Lovette describes an innovative study of the amazing travels of southern albatrosses

Albatrosses have a tendency to follow ships at sea. Although this behavior delights birders on pelagic trips, it is not always a good thing for the albatrosses. In Coleridge's poem "The Rime of the Ancient Mariner," the eponymous sailor tires of an albatross that perpetually follows his whaling ship through the southern ocean and shoots the albatross with a crossbow, thereby forever cursing his ship and himself. Today, the ill luck goes to the albatrosses: 19 of the world's 21 albatross species or subspecies are endangered, largely owing to mortality caused by longline and trawl-based fishing.

One barrier to switching to alternative fishing techniques that reduce the death of albatrosses is that we do not know much about where albatrosses go when they are away from their breeding colonies. Satellite transmitters have been used to track albatross movements, but the duration of these studies has been limited by the short life of the transmitter's battery. In a new study published in Science (January 14, 2005), a team of researchers from the British Antarctic Survey used a different technology to determine where 47 Gray-headed Albatrosses went after they left their breeding site on South Georgia, a remote South Atlantic island located 1,200 miles east of the southern tip of South America.

To the leg of each albatross, the researchers attached small data loggers that contained a clock to keep track of the date and time. More ingeniously, these devices also recorded light levels. By knowing the time of sunrise and sunset on each day the albatrosses were at sea, the researchers were able to determine the birds' latitude and longitude using essentially the same methods employed by sea captains wielding a chronometer and sextant. They retrieved the data loggers when the birds returned for their next nesting cycle, allowing the scientists to plot their movements for the preceding 18 months the birds spent away from shore.

The resulting maps of albatross movements are remarkable, allowing the researchers to identify three different dispersal strategies. Some birds remained relatively close to South Georgia, moving within the same foraging range they used when nesting. A different group of birds commuted east a third of the way around the globe, spent months in a food-rich region of the southern Indian Ocean, then retraced their path west back to South Georgia.

A final group of 13 birds made the most dramatic journeys of all, circumnavigating the globe from west to east. Three birds even made double circumnavigations in the 18 months between nesting cycles. These birds' average rates of movement were also impressive: many traveled at an average pace of 600 miles per day over long periods.

The movements of these seabirds across such vast distances demonstrate how albatross breeding populations on particular islands are vulnerable to sources of mortality thousands of miles from their nesting colonies. Conservation of such widely traveling species truly requires efforts

For permission to reprint all or part of this article, please contact Miyoko Chu, editor, Cornell Lab of Ornithology, 159 Sapsucker Woods Rd., Ithaca, NY, 14850. Phone: (607) 254-2451. email: mcc37@cornell.edu