I think you're taking an unnecessarily hard line. Flightless birds would, indeed, have to re-learn flight. It's not an exaggeration to say that. Sure, the basic

I think you're taking an unnecessarily hard line. Flightless birds would, indeed, have to re-learn flight. It's not an exaggeration to say that. Sure, the basic hardware is still there, since they are, after all, birds. But they're not flying anymore. Of course, they would not be starting from scratch.