Question

which birds cannot fly and why ?​

Answer 1

Flightless birds are birds that through evolution lost the ability to fly. There are over 60 species, including the well known ratites (ostriches, emu, cassowaries, rheas and kiwi) and penguins. The smallest flightless bird is the Inaccessible Island rail (length 12.5 cm, weight 34.7 g).