While I do want to get on the haydur train, I find it pretty hard to imagine how Ratso could have killed a flock of chickens. Anyone who has tried to kill a chicken knows it isn't easy, especially if they outweigh you, are taller than you, and you have bulging eyes. He would have been injured. Pine martens can do the job swiftly and for the sport of it, accessing the walled garden (if that's where the massacre took place), via trees on the outside and across and down the colonnade beams and pillars. They can leap six feet. And have been seen on Philip's forest web cam. Stephanie calls them stoats and says they've only had one previous poultry kill at Lalande. Completely doubtful.
And, poultry nurturers, don't foxes just carry away their dinner instead of killing everybody and taking nothing?