I was willing to accept an occassionally lost bird as the price paid for free ranging. But when the fox couple "hatched" three kits they were going through my hens like a knife thru butter. We "dispatched" dad who was way too bold around the farm humans. Put up electric around the barnyard itself where the hens spend most of their time. installed an automatic pullet shut door. AND then the four African/chinese geese matured. They approach everything as a group at top volume. We have not lost a hen since. Obviously a fox could dispatch a goose but I think that with the sheer noise level produced they leave looking for easier pickings.
I got my geese to protect my ducks during the day when they are out. Seems to be working for me. I have good fencing but living in the country with the feral cats, neighbors dogs, and a ton of other wildlife I like the fact that the geese make a big row when there is something. I also have the goose pen and duck pen right under my window so if anything does happen at night I will hear it and be able to respond. Its taken time to train him but my gander is able to usually keep keep quiet unless something is wrong. Knowing he is quiet gives me peace of mind.