Bird surname fortune telling

Why can a ghost bird pick out a surname?

Birds are professionally trained. Counting the surnames of soul birds is a folk trick. Soul birds repeatedly stimulate training by feeding. When the owner scatters bird food on the designated brand, the well-trained birds will bow their heads and pick out the brand, causing the illusion that the soul bird counts the surname. Therefore, the soul bird can pick out the surname because the soul bird has undergone professional training.