“We know that adults make these flights regularly, but a juvenile godwit has never before been tracked southward from Alaska,” Jesse Conklin, an independent researcher who first tagged the bird earlier this year, told Newsweek.

“There are a number of birds that make longer migrations in overall distance. But there is no other bird yet known that flies more than 11,000 kilometers [6.8 miles] and 9 to 11 days without stopping or eating,” Conklin said.

Conklin, who is based in California, carried out this research in association with the Max Planck Institute for Ornithology in Germany, the U.S. Geological Survey’s Alaska Science Center and the U.S. Fish and Wildlife Service’s Migratory Bird Program. “This particular track is part of a project to understand how young godwits learn or develop their adult routines,” he said.

“For this particular population of bar-tailed godwits, they follow a very predictable pattern,” Conklin continued. “Their annual journey is around 30,000 kilometers per year, more in some cases.”

After spending September to March in New Zealand and eastern Australia, the birds fly nonstop to the Yellow Sea region of China and the Korean Peninsula, a distance of 9,000 to 10,000 kilometers, he said. “After refueling on mudflats of the Yellow Sea, they fly eastward to Alaska, a nonstop flight of 5,000 to 8,000 kilometers, and breed there.

“After the breeding season, the entire population congregates on mudflats in southwest Alaska to prepare for the southbound trans-Pacific flight in September/October of 11,000 to 13,000 kilometers back to New Zealand and eastern Australia,” Conklin said.

During these flight periods, the birds do not rest, stop, eat or drink for over a week. Like any endurance athlete, they must spend weeks preparing for the grueling journey.

“Before these longer flights, they nearly double their weight in fuel over about two months and expend nearly all of that during the flight,” Conklin said. “So a godwit might fatten up to 500 grams in Alaska and arrive in New Zealand below 300 grams.”

The birds have also evolved several physical adaptations to help them complete this impressive feat.

“They have wing and body shape that makes them unusually aerodynamic, and they are a size that seems conducive for carrying sufficient fuel while maintaining a good relationship between air speed and drag,” Conklin said.

“They clearly have amazing navigation and orientation abilities that we only partly understand, and they are unusually good at quickly converting food into fuel, which mostly takes the form of burnable fat plus some measure of protein,” he said.

Conklin and the other researchers hope to continue monitoring the bird on the rest of its journey. “It currently remains in Tasmania, but we have to wait and see whether it eventually moves to New Zealand or mainland Australia during the coming months,” he said. “If all goes well, we may be able to follow this bird for years.”