Ovid [1st century CE] (The Metamorphoses, Book 14, 566-580): Ardea [a city] fell, spoken of as a power while Turnus lived. After the savage fires had destroyed it, and warm ashes buried its houses, a bird flew from the ruins, one now seen for the first time, and beat at the embers with flapping wings. Its cry, its leanness, its pallor, everything that fitted the captured city, even its name, ardea, the heron, survived in the bird: and in the beating of its wings, Ardea mourns itself. - [Kline translation]

Lucan [1st century CE] (Pharsalia, book 5, verse 622-635): "...a southern gale, the rest proclaimed / A northern tempest ... the heron used / To wade among the shallows, borne aloft / And soaring on his wings...".

Isidore of Seville [7th century CE] (Etymologies, Book 12, 7:21): The heron [ardea] is named as if the word were ardua (“steep”) – this is on account of its lofty flight. It is afraid of rainstorms, and flies above the clouds so that it cannot feel the storms in the clouds, and whenever it flies higher, this indicates a storm. Many people call it the tantulus. - [Barney, Lewis, et. al. translation]

Hugh of Fouilloy [ca. 1100-1172 CE] (De avibus, chapter 52): [The bird] is called a heron (ardea), as if to say 'high' (ardua) because of its lofty flights . . . for it fears rain and flies above the clouds so that it cannot perceive the storm clouds. Moreover, when it flies, that means a tempest [is coming]. Many people call this ]bird] Tantalus. Whence Hrabanus said, "This bird can signify the souls of the elect which, fearing the turmoils of this world, lest by chance through the Devil's plotting they be completely overwhelmed by the storms of persecution, raise their attention above all temporal matters, [and] their minds toward the clear weather of the celestial home, where they continually see the face of God." Granted that the heron seeks its food in the water, nevertheless it builds its nest in forests and in tall trees, because the righteous man who is maintained by fleeting and temporal things places his hope in exalted men: not only is his flesh nourished by temporal things, but also his soul is delighted by the eternal. With its beak the heron endeavors to defend the chicks in the nest, lest they be seized by other birds. In the same way, with forceful invective, the righteous man smites those wayward people whom he knows to be prone to deceit. Certain [herons] are in fact white in color, others ashen. Each color, however, is considered to good advantage, if by white is meant purity and by the ashen penitence; for both those who are penitent and those who live purely are of the same species. And therefore the color of the heron and its way of life provide to monks a model of salvation. - [Clark translation, 1992]

Thomas of Cantimpré [circa 1200-1272 CE] (Liber de natura rerum Birds 5.6-7): [Birds 5.6] Ardea, as Jacobus and Isidore and Ambrose say, was called 'steep', because of its 'high flights'. For it is afraid of the rain, and for this reason it flies above the clouds, so that it cannot feel the storms. Therefore, when it flies higher, it signifies a coming storm. Although this bird feeds in the water, it places its nest in the woods and high trees. And it is said that it strives to defend its young in the nest with great strength. The hawks are hostile to them, says the Experimentator. And the heron opposes the hawk by casting out its dung, at the touch of which the hawk's feathers rot. It has a single intestine like the stork. Some call this tantalum. Most of these birds have a gray color, but some are white. Pliny: There is a certain kind of them, the males of which, during copulation, cry out in great agony, and pour blood from their eyes in agony; nor do they mate with a pregnant female. Pliny calls this type of bird ardeales. [Birds 5.7] The ardee are said to have a certain genus, the birds of which genus differ from them only in their broad beaks. The muzzle is so wide in the anterior part as to exceed half a cubit, that it exceeds the measure of three fingers. This bird lives on fish, which, of course, when every attempt is frustrated, it pecks with its beak and swallows. Especially this kind has a cyan color. There are others, however, that shine with a white color. There is also a kind of them, as Pliny says, that has but one eye, from which it can see; from this it happens that it can be caught more quickly by fowlers. - [Badke translation/paraphrase]