for National Geographic magazine
For the first time, scientists have tracked entire migration routes of individual songbirds, following them thousands of miles further than in earlier studies and revealing the birds fly two to three times faster than previously known. The new information will aid future conservation efforts.
The researchers equipped 14 wood thrushes and 20 purple martins with tiny geolocators—the first tracking devices small and light enough for songbirds to carry—to map their round trip between North America and the tropics with unprecedented accuracy.
They tracked two purple martins for about 9,300 miles (15,000 kilometers), from Pennsylvania to the Amazon basin and back, and tracked five wood thrushes to Central America and back.
"This is a real breakthrough," said Bridget Stutchbury, a biologist from York University in Toronto and lead author of a paper detailing the results, which appears this week in the journal Science. Her team, she said, was able to "accurately track where the birds spent the winter and how they got there" from their breeding ground in Pennsylvania.
"For most people studying migratory birds, this has been a daydream for years," said Stutchbury, who received funding for the study from the National Geographic Society's Committee for Research and Exploration and worked in collaboration with the Purple Martin Conservation Association.
(Read a related National Geographic News story: "Where Are All the Migratory Birds Going?"
Super-Fast Birds "Breaking All the Rules"
Stutchbury and her team released their birds in summer 2007 and snagged returnees the next spring, along with data on their routes and migration rates.
The birds' travel speeds astounded them. All flew two to six times faster during their spring return journey than in fall. One female purple martin dashed back north in 13 days at a speed of about 358 miles (577 kilometers) a day, shattering previous estimates for songbirds of 93 miles (150 kilometers) a day.
"Maybe this is some kind of super-bird, but still I was really impressed that any bird can do this," Stutchbury said. "These birds are traveling really fast and breaking all the rules."
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