<Li> Roviana rail, Gallirallus rovianae (flightless, or almost so) </Li> <Li> Tahiti rail, Gallirallus pacificus † </Li> <Li> Dieffenbach's rail, Gallirallus dieffenbachii † </Li> <Li> Chatham rail, Cabalus modestus † </Li>

When did chickens lose the ability to fly