Pretty amazing birds we have here, these Godwits. Or "Bar-Tailed Godwits" to be more precise. Seems they have been flying from Alaska to New Zealand in the course of their migration. Non stop, actually, out over the sea. The more industrious of the lot, anyway. That means they fly up to nine continuous, uninterrupted days, without rest. The lower achievers only make it four or five days, and stop for a spell to "refuel" for several weeks at a time. The truly hearty, howver, make it in one leg.
Their metabolic output while in flight can be 8-10 times their base metabolic rate. They keep this up for days on end without food or rest. As a point of reference, Lance's metabolic rate probably approached six times his base metabolic rate while on the toughest climbs of the Tour. And he got to eat and sleep every day...
http://www.nzherald.co.nz/animal-science/news/article.cfm?c_id=332&objectid=10462874