Mallard duck movie

There seems to be a sort of highway from one group of ducks to another. The coots (I can see 3-4, here) patrol alongside it and often chase away ducks that head toward the "wrong" group. That's the way I saw it, anyway, during my unscientific observation. Coots are so aggressive that I think if their protective behavior was about food supply, they would have chased the shore ducks away, too.

I tried to capture the coots chasing and shrieking at ducks, but they stopped as soon as I turned on my camera.

Any waterfowl experts in the house?