A young bird named B6 amazed the world by flying 13,560 kilometres from Alaska to Tasmania without stopping, setting a record.
This four-month-old bar-tailed godwit covered the distance in just 11 days back in 2022, setting a record for the longest non-stop flight by any animal. Tracked by a satellite tag from the US Geological Survey (USGS), B6’s trip highlights the wonders of bird migration.
Similar feats happen every year, like the Amur falcons that took flight from India and flew thousands of kilometres, going all the way to another continent. But what does it really take to cover such vast distances?
WHAT ARE BAR-TAILED GODWITS?
The bar-tailed godwit is a large shorebird renowned for performing the longest nonstop migratory flight of any bird on Earth.
Breeding across Arctic regions of Alaska and Siberia, the bird undertakes a biannual journey to its wintering grounds in New Zealand and Australia. The Alaska-to-New Zealand route spans approximately 11,000 kilometres, completed in roughly nine days without resting, eating, or drinking.
Flying continuously over the open Pacific Ocean, godwits navigate using celestial cues, magnetic fields, and an internal compass of astonishing precision.
Tracked individuals have sustained speeds exceeding 55 kmph, making the bar-tailed godwit an unrivalled migratory species of bird.
HOW DO BIRDS FLY LONG DISTANCES?
Birds like B6 or the Amur falcons face huge challenges during migration. They cross vast oceans with no land in sight, no food, and no rest spots.
B6’s journey beat previous records, flying over the Pacific Ocean through changing weather. Birds usually adapt to such trips, with many species, including those visiting India in winter, travelling from cold northern areas to warmer spots.
In India, bar-tailed godwits can be seen along coasts during migration seasons, adding to the country’s rich bird diversity.
To prepare, B6 ate a lot in Alaska, building up fat that made up half its body weight.
During the flight, the bird adapted by changing its body; it shrank organs like the stomach and liver to save energy and reduce weight. This trick helps burn fat efficiently,
Birds flying over deserts and seas also rely on adaptations to survive such marathons, where they adjust their bodies to survive without eating or drinking for days.
HOW DO BIRDS NAVIGATE?
Navigation is key during such flights, especially over endless water.
B6 used Earth’s magnetic field as a natural compass. Special proteins in its eyes, called cryptochromes, detected these fields, guiding it straight to Tasmania.
This built-in GPS in birds’ brains turns on during migratory flights to help guide them to their destination. Studies have shown birds also use stars, the position of the Sun, and even smells to navigate. But for long ocean crossings, magnetic sensing is crucial.
B6 also didn’t land for 11 days, but it rested in the air using what is called unihemispheric sleep. That is the process where one half of the brain sleeps while the other stays alert to keep flying. It’s like napping with one eye open.
Migratory birds also change altitude over different terrains to help them save energy. They fly higher over hot deserts to stay cool, lower over water for better air flow, helping them conserve energy.
The record set by B6 reminds us of nature’s marvels and the need to protect migration routes. As climate changes, birds face more threats, but stories like B6’s inspire conservation efforts worldwide.
