Abstract In an early theory of Aristotle, redstarts can turn into robins in the winter. Book of Rites also mentioned the transformation of birds. For example, the eagle turns into a cuckoo in the spring and transforms back to what it was in autumn. To provide a modern point of view for these descriptions, the author investigates the correlation between the transformation and the behavior of birds. It is found that these descriptions were probably resulted from the faulty observations of bird migration by ancient people.