8,425 miles. 11 days. Zero rest stops. A juvenile godwit crossed the entire Pacific on its first try — fueled by nothing but fat.
A bar-tailed godwit (Limosa lapponica baueri) holds the verified record for the longest nonstop flight by any animal: 8,425 miles from Alaska’s Yukon-Kuskokwim Delta to Ansons Bay, Tasmania, completed in 11 days and one hour without landing, feeding, or resting. That record belongs to a juvenile — a bird making the trip for the very first time.
What makes the biology stranger still is what happens before the bird ever leaves the ground. For roughly two months at the Yukon Delta, godwits feed intensively on clams and small worms, doubling their body mass. By departure, 50–55% of that mass is pure fat. The body that lifts off is more fuel tank than bird.
How Bar-Tailed Godwits Shrink Digestive Organs Before Migration
To carry that fat load, something has to give. Before departure, godwits reduce the size of their digestive organs — intestines, stomach, liver — freeing mass and space for fuel storage. Wikipedia’s entry on the species notes they carry the greatest fat loads of any migratory bird studied, specifically enabled by pre-departure reduction of digestive organ size. These organs aren’t needed mid-ocean. There’s nothing to digest.
After landing, feeding resumes and those organs rebuild. The architecture is temporary by design.
What Powers 8,425 Miles of Open-Ocean Flight
At takeoff, roughly half the bird’s body is fat. That fat is the sole energy source across an ocean that offers no islands, no rest stops, and no food. Animals Around the Globe, summarizing tracking data, notes the Pacific route from Alaska to Australasia has no landmasses for potential stopovers — the flight is nonstop by geographic necessity as much as physiology.
Tracking studies document average ground speeds around 30–35 mph, with bursts well above that when tailwinds cooperate. The 2022 juvenile “B6,” whose flight set the Guinness-recognized record, maintained that pace for 11 days straight.
The Juvenile Record Flight Specifically
The juvenile godwit B6 departed the Yukon-Kuskokwim Delta and landed at Ansons Bay, Tasmania. The Guinness organization confirmed it as the longest nonstop animal flight on record. An adult male tagged 4BBRW had previously held the title, with a 2020 flight of approximately 7,580 miles from Alaska to New Zealand. In 2021, that same bird flew more than 8,100 miles to New South Wales, flapping continuously for 239 hours.
The record keeps moving. Each new tracking season brings satellite data on birds pushing the documented edge a little further.
Forty years of watching birds, and the godwit still lands differently than everything else. It doesn’t stop. It just arrives.
Frequently Asked Questions
How far does a bar-tailed godwit fly nonstop?
The verified record is 8,425 miles, set by a juvenile flying from Alaska to Tasmania in 11 days. Routine Alaska–New Zealand flights exceed 7,000 miles nonstop.
Why do bar-tailed godwits shrink their organs before migrating?
Reducing digestive organ mass before departure allows the bird to carry larger fat loads. Those organs rebuild after landing when feeding resumes.
What percentage of a godwit’s body is fat at takeoff?
Approximately 50–55% of body mass at departure is fat, confirmed by researcher Robert Gill in NPR reporting.
Has a juvenile godwit really made this crossing before?
Yes. The 8,425-mile record flight to Tasmania was completed by a juvenile bird on its first migration, with no prior experience of the route.