The Chaucer Review: An Indexed Bibliography (Vols. 1-30)

Hirsh, John C. "Classical Tradition and The Owl and the Nightingale." 9 (1974): 145-52.
Writers such as Gregory of Nyssa, Pythagoras, Plato, and Ambrose connect jackdaws to owls when presenting metempsychosis. As the owl only flies at night and was supposedly ashamed of this fact, the owl offers some comic possibilities.