Part of the fall migratory route of the Blackpoll Warbler is over the Atlantic Ocean from the northeastern United States to Puerto Rico, the Lesser Antilles, or northern South America. This route averages 3,000 km (1,864 mi) over water, requiring a potentially nonstop flight of up to 88 hours. To accomplish this flight, the Blackpoll Warbler nearly doubles its body mass and takes advantage of a shift in prevailing wind direction to direct it to its destination.[Source]
These birds are amazing — they literally bulge with stored fat just before they make this journey. I’ve heard a fellow ornithologist say that if blackpolls burned gas for energy they would get the equivalent of 200,000 miles per gallon.
That. Is amazing.