From Barbara G. Walker's "A Woman's Encyclopedia of Myths and Secrets." See also prior posts on Athena:
Romans called the owl strix (pl. striges), the same word that meant "witch."(1) Greeks said the owl was sacred to Athene, their own version of the ancient Mesopotamian "Eye-Goddess" whose staring owl-eyed images have been found throughout the Middle East, especially around the Mother-city of Mari.(2) The owl was also the totem of Lilith, Blodeuwedd, Anath, and other versions of the Triple Goddess of the moon. See Trinity.
According to Christian legend, the owl was one of "three disobedient sisters" who defied God and was transfrmed into a bird who never looked at the sun.(3) It is easy enough to see in this idea the shape of the Goddess herself, and the church's hostility to her. One of the medieval names for the owl was "night hag;" it was said to be a witch in bird form.(4) The owl is still associated with witches in the smbols of Halloween.
The owl is also a bird of wisdom because it used to embody the wisdom of the Goddess. Certain medieval magic charms apparently sought to use the bird's oracular power against its former mistress, woman. If an owl could be slain and its heart pulled out and laid on the left breast of a sleeping woman, the owman would talk in her sleep and reveal all her secrets.(5) This seems to have been the basis of the expression, "heart-to-heart talk," which meant a woman's secret conversation with her familiar.
(1) Trigg, 96.
(2) Neumann, G.M., pl. 87.
(3) de Lys, 37.
(4) Cavendish,P.E., 100.
(5) Agrppa, 76.