A recent article in the NYTimes about probably the world champion of endurance - that is the Bar-tailed Godwit - a bird that migrates between New Zealand and Alaska.

This bird's migratory pattern was just recently discovered, after tracking devices were attached to some of the birds. These birds fly the 7000 miles between Alaska and New Zealand without stopping to rest, to eat, to have water, or to sleep. They fly between 3 and 5 miles high in altitude. The flight takes up to 10 days.

story is here: