If your going to free range your birds accept the fact your going to lose some. It isn't the predators fault your offering them a meal, their just doing what comes naturally. We as humans, should be smarter than, say a silly ole marsupial, especially a Possum. Kill one and you just saved the lives of thousands of ticks and other pesky bugs and things they eat. Same goes for other predators, there is always consequence in the balance when you kill them.