quote:
In the cases of the ostrich, moa, and other larger flightless birds, in the ones which survived the changes in gravity which killed off the larger dinosaurs, they had gotten too heavy to fly (~30-lb limit in our present world) and the wings became vestigial.
Is there a 30 lb. limit in our present world? Is that too heavy to fly...?
The heaviest flying bird is the Kori Bustard of Africa (Ardeotis kori), a number of specimens have been scientifically recorded weighing 19kg (42lb) and heavier specimens have been reported but not confirmed. Close runner-ups are the Eurasian Bustard (Otis tarda) and the Mute Swan (Cygnus olor) both of which have been recorded at 18kg or (40lb).
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