[Of the heron] It is called heron, ardea, as if from ardua, meaning ‘high’, because of its capacity to fly high in the sky; it fears rain and flies above the clouds to avoid experiencing the storms they bring. A heron taking wing shows a storm is coming. Many people call the heron Tantalus, after the king who betrayed the secrets of the gods. Rabanus says on this subject: ‘This bird can signify the souls of the elect, who fear the disorder of this world, lest they be caught up by chance in the storms of persecution stirred up by the Devil, and raise their minds, reaching above all worldly things to the tranquility of their home in heaven, where the countenance of God is forever to be seen.
Although the heron seeks its food in water, nevertheless it builds its nest in woodland, in tall trees, as the righteous man, whose sustenance is uncertain and transitory, places his hope in splendid and exalted things. The soul of man sustained by transitory things, rejoices in the eternal. The heron tries with its beak to prevent its nestlings from being seized by other birds. So the righteous man lashes with his tongue those who, to his knowledge, are evilly inclined to deceive the gullible. Some herons are white, some grey, but both colours can be taken in a good sense, if white signifies purity, grey, penitence.