Seven black robins were left, then five, and among them a single female still able to lay a fertile egg. Her chicks went to foster parents so she could lay again: warblers underfed them, and tomtits raised them so convincingly that the chicks grew up believing they were tomtits and would court nothing else. Returned to Old Blue, they thrived. She lived to fourteen, raised eleven, and all 250 black robins alive today are hers.