In 2007, an Alaskan bar-tailed godwit (Limosa lapponica baueri) flew 11,000 kms over 8 days from Siberia to New Zealand. Nonstop. Thats without feeding, sitting down on the ocean to rest, or calling in for a break at a tropical island on the way. In Plos Biology this week, Anders Hedenström looks at the physiological and aerodynamic requirements for such feats of endurance, and finds that current models can explain such feats.
Hedenstrom compared the rate of fuel consumption in godwits with that of other birds, and found that godwit’s fuel consumption is very efficient, but lies within a normal range. The godwits body shape and flight speed also mean it is close to the “optimal design” for long-distance flight from an aerodynamic standpoint. However, many shorebirds share these features and once again the godwit doesn’t stand out as being exceptional. Hedenstrom suggests that the godwit may stand out from other birds in its ability to navigate, but exactly how the birds maintain their orientation during their non-stop flight across the ocean remains a mystery.
Reference: Hedenström A (2010) Extreme Endurance Migration: What Is the Limit to Non-Stop Flight? PLoS Biol 8(5): e1000362. doi:10.1371/journal.pbio.1000362