The giant albatross has the biggest wingspan at around 3.7m (12 feet). The male kori bustard's wingspan is only around 2.7m, but it's much heavier.

Other weight rivals are the Dalmatian pelican and Andean condor, whose average weight is more, but they don't have the big male/female weight disparity.

The heaviest male kori bustards weigh over 20kg and cannot fly.