Watch Les Oiseaux de la lune (1974) Official Trailer

Valentin, the general supervisor of a sub-prefecture cram school, has a strange power: all he has to do is wish for a certain person to turn into a bird, and the metamorphosis takes place and his victims grow wings. He's in love with Sylvie, the young lady coveted by all the local males. This is how an entire small population loses its human appearance.