I used to have a lot of problems with hawks when I first got ducks, however I was able to master the art of protecting them. Now several years later and a new (and large) coyote problem has forced me to pen in all of my poultry (Now including Geese and Guineas on top of ducks). I bought over 300 feet of fencing, I do not however plan to use all of it. It will be large, and has to be, however I have not thought of any type of top for it. And with the size I am thinking of the top would have to be made out of string of some sort. So my real question is If I will see a return to my hawk problem? I have not seen any hawks around my house in several years, but their return may be inevitable. My ducks are Peking and Rouen ducks.
I remember seeing some nice poultry netting on Amazon, and the price seemed to be reasonable as well. Other than that, I suppose you know of hanging old CD's on a string and other shinny things to deter the birds of prey. As far as that goes you could use twine every few feet crossed to and fro. I understand that the hawks can see this, but this is a problem I have not had as of yet. Best to you and your birds, RJ