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.

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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.

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