A mate of mine has pylons a few hundred yards from his loft and loses a few y/birds each season to them.We watched his youngsters flying around his lofts and they appeared to be drawn towards them,when they got near the pylons they were confused and split up some tried to fly through them and dropped like stones killing about a dozen,the rest just circled for a while before returning to the loft and weren't spooked in any way.His lofts are on farm land and the pylons are easily visable to the birds,he doesn't get this problem with old birds.