Your results alone are a far cry form what is required to refute the value of the CD's. More people having tried need to come forward indicating results of using them.It was suggested to me to hang CD's in my fruit tree's to keep birds away. What do I know?? so I tried it...It actually appeared to work..but only for a very short time..The birds got used to them and continued there feast...
So the question one has to ask themselves is...are you willing to gamble and/or risk the protection of your birds on hanging CD's? Only you can answer that....
If hawks cannot get to your birds, they can't kill them.