In 2022, a four-month-old bar-tailed godwit left Alaska on its first migration; it flew 13,560 km nonstop and reached Tasmania 11 days later

On October 13, 2022, a juvenile bar-tailed godwit, scarcely four months old and weighing less than a can of beans, took flight from the mudflats of western Alaska and kept going without stopping to eat, drink, or rest its wings in any way at all. Eleven days and one hour later, it landed on the shores of Tasmania, Australia, having flown an incredible 8,425 miles without a single break in the open ocean.

According to the U.S. Geological Survey, which monitored the route taken by the bird along with scientists at the Max Planck Institute for Ornithology and the U.S. Fish and Wildlife Service, the non-stop flight represents the longest distance ever covered without pause by any bird.

Researchers in the field knew this bird as "B6," from the black leg flag it carried; its satellite tag was numbered 234684, the identifier used in the Guinness World Records listing. Guided by data from that tag, scientists were able to trace its entire route in real time, though it was the very first time in the bird's life that it had made this specific crossing.


How do you fly for 11 days without stopping

The short explanation: the bird stores enough fat to fuel the entire migration, then burns through it at a punishing rate. Before the departure of B6 from Alaska, the godwit was fattening itself up on clams, worms, and other invertebrates along the Kuskokwim Delta region of Alaska until its body was full of enough fat to power the whole migration. In the lead-up to departure, bar-tailed godwits also shrink certain internal organs, including parts of the digestive system, since they are dead weight once the bird is airborne and live off stored fat instead of food.

But that's not all; it's not even an extraordinary feat. As mentioned in a ground-breaking 2008 study titled “Extreme endurance flights by landbirds crossing the Pacific Ocean: ecological corridor rather than barrier?,” by Gill et al., in the Proceedings of the Royal Society B, migrating bar-tailed godwits sustain metabolic rates nearly eight to ten times greater than the normal resting metabolic rate for over a week in duration, which is unmatched by any other animal of the natural world. Simply put, it is more like a week-long ultramarathon rather than a "long flight," except it is being run across the open sea without anywhere to rest.

The record kept getting broken, and that's the point

B6 is not the first Bar-tailed Godwit to have made a record. In 2007, E7, a female Godwit, broke a new mark of eight days of flight without stopping. In 2020, a male named 4BBRW flew more than 12,000 km from Alaska to New Zealand in 11 days. But all these were beaten by a young one, B6, which had not grown fully yet. According to the Guinness World Records, B6 flew a distance of approximately 13,560 kilometers non-stop.

It should not come as a surprise if this world record is broken again. This is simply because there is not much known about the outer limits of a bird's physiology and how much they can endure, with the available resources to study this field in further detail. This is something that requires biologists to work in the field for many years and attach 5-gram transmitters onto chicks.

Why this matters beyond the trivia

There is a reason why such facts about wild animals should be considered beyond mere trivia. These marathon migrants depend entirely on being able to fuel up before they fly: the two months B6 spent fattening up on the Kuskokwim Delta made the entire nonstop crossing possible.

The birds that make such crossings are increasingly vulnerable due to coastal habitat losses along the Pacific Flyway, and the more flights that are tagged like B6, the more the scientists understand which stopover sites, like the Alaska tundra it grew up on, are necessary for the birds' survival. No matter how many times the birds manage to endure the trip, if these sites where they are able to accumulate energy are gone, the chances of their survival become zero.