Gray-headed albatrosses, famed for flocking to the South Georgia Islands near Antarctica to mate and raise chicks, routinely circle the globe between breeding seasons in a restless search for fish, British scientists discovered.
For a study appearing this week in the journal Science, researchers for the British Antarctic Survey attached electronic locators to the legs of 22 birds. They provided the first strong evidence of how the graceful south sea fliers spend their time outside of the breeding season.
The breeding season comes every other year, but little was known where the birds went when they were not raising young.
The sensors put on the birds recorded their location twice a day for 18 months. When the scientists recovered the tracking devices, the downloaded data gave a history of the wanderings of each bird.
The researchers found that more than half of the birds flew completely around the world, following the chilled oceans below 30 degrees latitude south. One bird circled the globe three times in 18 months, and another flew more than 13,000 miles in just 46 days.
The purpose of the study was to find why the albatross has become one of the most threatened family of birds on Earth, the researchers said. Learning about their migration and feeding habits could lead to policies protecting them from long-line fisheries that kill an estimated 300,000 of the birds annually, the study said.
"By understanding where these birds go when they're not breeding, we can brief governments and fisheries commissions to impose much stricter measures capable of reducing the number of birds killed," said John Croxall, a British Antarctic Survey scientist and first author of the study in Science.
"The right combination of measures will drastically reduce deaths," Croxall said in a statement.