This thread contains comments made on http://www.rspb.org.uk/film/10683638.aspx.
Delighted to watch this film - I live in southern France (near little town of Carmaux)and was out sketching in our hamlet when I heard the sound of a distant flock of birds. When they came closer I was amazed to see hundreds of a large bird in perfect skein formation, flying northwards. My partner thought they were geese but I was not convinced. I drew a quick impression of this event, and dated it - 1st March. Having seen your film and investigated their migration route I am now convinced that we saw Cranes on their way up to the north of France/ Germany. I will never forget witnessing these wonderful birds in flight.
Never turn your back on a rat