A godwit's flight

The bar-tailed godwit flies 6,800 miles each year from Alaska to New Zealand without food, water or rest...and the semipalmated sandpiper, small enough to fit into a teacup, migrates between South America and the Arctic, “through gales and hurricanes, over mountains and ocean.”

-- Theodore Cross's Waterbirds


Bar-tailed godwits cover the distance in eight days, which means a continuous average speed of no less than 30mph, or about 50kmph.