It is a fact of life, but not much you can do. My moggie came home with a sparrow in its mouth I managed to get it off him, he was mortified and tried to follow his prize. I took it upstairs out of his way, put it in a dish lined with an old sports sock and hoped it would be able to sort itself out on the windowsill outside. I kept checking on it for about an hour then the bird rallied round, I was thrilled, it then took off like a kamazi pilot and fell flat on it's beak on the flat roof below the window. End of sparrow and I couldn,t get to it to clear it off the roof...the cat slunk off.