Cultures all around the world have used bird imagery in their folklore, poems and literature for thousands of years. The ancient Greeks, Egyptians, Persians and Hebrews incorporated birds into religious symbolism. Birds are often representative of transcendent spirituality due to their ability to fly and sing. From the ancient Greek poet Homer to the 19th-century romantic poet Samuel Taylor Coleridge, the bird encompassed everything humanity failed to grasp or died trying to understand.
One ancient Greek story involving birds is a tragic one and has undergone revision through the years. King Tereus seduces, rapes and cuts out the tongue of his sister-in-law Philomela. She and her sister Procne then collaborate to kill Tereus's son Itys, chop up his body and serve him as a meal to the unsuspecting Tereus. Once Tereus discovers the truth, he prepares to kill the sisters. The gods intervene and turn everyone into birds. Philomela becomes a swallow, Procne a nightingale, Tereus a hoopoe and Itys a pheasant. The story may have attempted to explain the sad song of the nightingale and the swallow's inability to sing at all. Many stories worked on the premise that when people passed away, their souls were reincarnated into animals they may have resembled during their lifetime.
Renaissance poets enjoyed using bird imagery, especially in their love poetry. Lovesick men were compared to nightingales, singing endlessly of their hopeless love. The object of their adoration was embodied in a rosebush, beautiful but full of thorns. The nightingale would lean against the rosebush to feed off the nectar of the flower, whereby the thorns would pierce the breast of the nightingale and draw blood. Such an image evoked the heartbreak endured when the woman would deny her admirer's advances. The sharp thorn would later become Cupid's arrow. Richard Barnfield wrote of the nightingale's sorrow in "The Ode":
"She, poor bird, as all forlorn,
Lean'd her breast up-till a thorn
And there sung the doleful'st ditty,
That to hear it was great pity.
Fie, fie, fie, now she would cry,
Teru, teru, by and by."
Ancient religions were in awe of birds that appeared to fly so close to the sun, the source of all life. Early Egyptians, Hindus and Sumerians believed that birds such as eagles, vultures and hawks were sky-gods. The egg became a universal symbol for fertility and the miracle of birth. The Egyptians worshipped Horus and Ra, gods with human bodies and falcon heads. Many of the Greek gods were associated with birds: Zeus had the majestic eagle, Hera was the proud peacock, Athena resembled the wise owl and Aphrodite was the beautiful dove or swan. The image of the eagle representing authoritative power has endured from Caesar's rule to American democracy.
The Hebrew Bible often compared God's majesty and protection of His people to that of a mother bird. Isaiah 31:5 says: "Thus the Lord of Hosts, like a bird hovering over its young, will be a shield over Jerusalem." Early Christians employed bird imagery to attract converts; they compared Jesus to the phoenix rising from the ashes or to the eagle that finds its source of strength from the sun. Jesus was also compared to the pelican, which, according to ancient belief, would tear its breast open in order to feed its young. Thomas Aquinas, a medieval theologian, described the comparison: "Bring the tender tale true of the Pelican;/ Bathe me, Jesu Lord, in what thy bosom ran/ Blood that but one drop of has the world to win/ All the world forgiveness of its world of sin."
Romantic poets compared a caged bird to a human being denied his or her natural right to freedom. Charlotte Bronte's popular heroine Jane Eyre resembles a caged bird, one whose potential has been trapped by unfortunate circumstances. Her employer, Mr. Rochester, is the only character who recognizes this tragedy for what it is: "I see at intervals a glance of a curious sort of bird through the close-set bars of a cage; a vivid, restless, resolute captive is there; were it but free it would soar cloud-high." Thomas Hardy's tragic Tess of the d'Ubervilles features Tess, a woman who meets tragedy all throughout the novel and is often compared to a timid bird that cannot break free. Hardy employs images of nests and feathers when he describes Tess's entrapment and beauty.
The Romantics put particular emphasis on the nightingale, the bird traditionally known to sing through the night. The poets saw the nightingale as a natural representation of the poet's condition and inspiration. Romantic poets such as John Keats, Percy Bysshe Shelley and Edgar Allen Poe were themselves inspired by the idea that the bird sings for its own sake.