Eleven Days
Without Landing
In October 2022 a five-month-old bar-tailed godwit left western Alaska and did not touch ground until Tasmania. No food, no water, no rest — across the entire Pacific. The map shows the route; the numbers show why the bird’s real weak point isn’t the ocean, but a coastline it needs on the way back.
The longest nonstop bird flight ever tracked. Juvenile godwit #234684, satellite-tagged by researchers working with the Max Planck Institute of Animal Behavior, flew from the Yukon–Kuskokwim Delta to Ansons Bay, Tasmania, in about 11 days (Guinness World Records, 2023).
A straight shot down the widest ocean
Godwits leave Alaska in autumn and head south across open Pacific. There are islands below, but a shorebird can’t feed on them, so it keeps going.
The 2022 juvenile took off from the Yukon–Kuskokwim Delta on 13 October and kept flapping for about 11 days. It crossed the equator and the 180th meridian without stopping, and made landfall at Ansons Bay on Tasmania’s north-east coast.
Most of the population, the baueri subspecies, aims for New Zealand instead. The female known as E7 flew to the Firth of Thames in 2007. Her flight was the first one tracked end to end, and it was published in Proceedings of the Royal Society B (Gill et al. 2009).
The 2022 juvenile ended up farther west than most, in Tasmania rather than New Zealand, but still within its population’s wintering grounds.
Southbound: Alaska → Tasmania or New Zealand, nonstop, in autumn.
Northbound: New Zealand → Yellow Sea → Alaska, in two long hops with a refuelling stop on the tidal flats.
The loop takes the birds round the whole western Pacific every year.
Three birds, three nonstop records
Each new record flight broke the last one. All three are bar-tailed godwits flying the same Alaska-to-Southern-Hemisphere route.
E7 set the benchmark in 2007 with 11,680 km in 8.1 days. In 2020 an adult male tagged 4BBRW logged 12,200 km to New Zealand, a Guinness-recognised record. Two years later a juvenile on its first migration beat that by 1,360 km.
13,560 km is about a third of the way around the planet (Earth’s equator is 40,075 km). No other land bird is known to fly so far without stopping.
Half bird, half fuel tank
To carry enough energy, godwits convert more than half their body into fat, and shrink the organs they won’t use in the air.
Godwits killed in a collision in Alaska just before departure had fat loads of about 55% of fresh body mass. Piersma & Gill (1998) called this among the highest ever recorded in birds.
The same birds had unusually small gizzards, livers, kidneys and guts. Organs needed for digesting food are dead weight on a flight with no food. The birds rebuild them after they land.
The coastline the whole loop depends on
Coming back north, the godwits stop once: on the mudflats of the Yellow Sea, between China and the Korean Peninsula. Those mudflats are being filled in.
Comparing satellite images, Murray et al. (2014) found that Yellow Sea tidal flats shrank by 28% between the 1980s and the late 2000s, from about 545,000 to 389,000 hectares. Most of the loss was land reclamation for ports, cities, farms and aquaculture.
Historical maps suggest up to 65% has gone since the 1950s. That figure is an estimate over a longer window, so it isn’t directly comparable with the 28%.
The more a bird needs the Yellow Sea, the faster it declines
Studds et al. (2017) tracked ten shorebird taxa from 1993 to 2012. A population’s dependence on the Yellow Sea was the best predictor of its decline.
Bar-tailed godwits come in two populations on this flyway. Every menzbieri godwit refuels in the Yellow Sea; that population fell about 6.1% a year. Only about half of the baueri godwits (the long-haul Alaska birds on our map) depend on it, and they fell about 1.4% a year.
Compounded over 19 years, those annual rates are the difference between keeping three-quarters of a population and keeping less than a third. The lines are modelled from the published rates, not raw counts.
What to notice on the map
The ocean is the easy part. The risk sits on a single coastline.