This was a wonderful story in the Times about the godwit, which holds the record for the longest annual nonstop migration for a land bird – over 7,000 miles, from Alaska to New Zealand! And that’s over 8-10 days, no stops for food or water, and flight by continuous flapping, not dynamic soaring. Their round trip migration is about 30,000 km, since the return trip includes a stopover in China.  Scientists do not completely understand the birds’ physiology, since all models predict they should not have the available energy stores to make such a nonstop flight.  An excerpt:

‘…they are proficient at the incredibly risky endeavor; the survival rate is more than 90 percent.

“It’s not really like a marathon,” said Christopher Guglielmo, an animal physiologist at Western University in London, Ontario, who studies avian endurance physiology. “It’s more like a trip to the moon.”’

Amazing stuff.