Just a brief note to clarify the Gadwall/Coot relationship referred to in Richard's earlier post. It is actually the Gadwalls that are accompanying the Coots - to collect the weed/Chara that is loosened while the Coots dive for food. BWP mentions a case at Bodensee in Germany where the Gadwalls are totally dependent on the Chara brought to the surface by Coots. Also, if you watch the ducks at Bosherston, you will see that it is the Coots that are chasing off the Gadwalls.
