Bar-Tailed Godwit Sets Record for Long-Distance Flight

How is it possible to fly 11,000 kilometers without a single break? The record holder for long distance flight outdoes all human-made aircraft. Every year the Bar-tailed godwit undertakes an eight-day journey of 11,000 km between Alaska and New Zealand twice. The bird flies non-stop, without once breaking the journey to rest or eat.

Professor of Ecology Anders Hedenström from Lund University has pondered over how this species of bird can fly so far without stopping. The distance is twice as far as previously known non-stop distances for migratory birds.

Professor Hedenström emphasises that the bar-tailed godwit is far superior to all aircraft constructed by humans when it comes to the art of flying for a long time without a break. The best man-made flying machine with a record closer to that of Bar-tailed Godwit is QiniteQ's Zephyr, an unmanned solar-powered craft which remained in the air for 82 hours, (around 3.5 days), compared with the Bar-tailed Godwit's eight-day flight.

But what is it that makes the bar-tailed godwit able to fly 11 000 kilometres without a single break? How can these birds manage without sleep or food for eight whole days? One explanation is that they consume unusually little energy compared with other species of bird. Anders Hedenström has calculated that the bar-tailed godwit consumes 0.41 per cent of its body weight each hour during its long flight. "This figure is extremely low compared with other migratory birds," he says.

There are still pieces of the jigsaw missing that could explain the bar-tailed godwit's record non-stop flight. Could the bird's success be due to a particularly good ability to navigate with the help of an inner compass that makes use of the earth's magnetic field, for example? Anders Hedenström notes that there are a number of exciting questions surrounding the bar-tailed godwit's ability not to get lost up in the air.


Read the full story here.

Read the journal article “Extreme Endurance Migration: What Is the Limit to Non-Stop Flight?”
Photo: Lars Hedenström (www.sciencedaily.com)