The 48 " might stop your birds from flying over. I got it a couple of years ago after watching a feral cat sail over the 36 inch net. Feral cats are a problem for me because my nearest neighbor, an elderly widow, feeds them. Then she leaves for a two week cruise several times a year, and the cats get hungry. I lost two hens to those cats before I put up the taller net. I have never had a hen fly over it. And back to cats, a neighbor's housecat got caught and entangled itself in the net. We found it early one morning, crying, naturally, since the fence pulses kept zinging it. We had to cut the fence to get it out but it has never been seen over here since. Hawks have dived into my area within the netting but have never taken anything yet. Sometimes they come down very close to me but always flee away at the sight of the chicken woman!