The caladrius is an all-white bird that lives in the king's house. If it looks into the face of a sick man, it means that he will live, but if the caladrius looks away, the sick man will die of his illness. To cure the sick man, the caladrius looks at him, and drawing the sickness into itself, the bird flies up toward the sun, where the disease is burned up and destroyed. The caladrius is an unclean bird which must not be eaten.

Allegory/Moral

The caladrius represents Christ, who is pure white without a trace of blackness of sin. Because the Jews did not believe, Christ turned his face from them and toward the Gentiles, taking away and carrying sins to the cross. Christ turns away from the unrepentant and casts them off; but those to whom he turns his face, he makes whole again.

Sources (chronological order)

Plutarch [c. 80 CE] (Symposiacon, book v, prob. 7, Druce translation): ... we know how often those who suffer from jaundice are healed by looking at the bird charadrius. This small animal seems to be endowed with such a nature and character, that it violently attracts to itself the disease, which slips out of the body of the sick man into its own, and draws off from his eyes as it were a stream of moisture. And this is the reason why the charadrius cannot endure to look at jaundiced persons nor help them at all, but turns itself away with closed eyes; not because it grudges the use of the remedy which is sought from it, as some consider, but because it might be wounded as by a blow.

Aelian [3rd century CE] (De natura animalium, Book xvii, chapter 13, Druce translation): Now this is the natural power of the charadrius, which by Zeus it is not right to despise. If a man has his body full of jaundice and then looks keenly at the bird, and the bird looks back at him very inflexibly, as though being made angry with him in return, then this mutual gaze cures the man of the aforesaid complaint.

Philippe de Thaon [12th century CE] (Bestiaire, Druce translation): Caladrius is the name of a bird, which we find without any doubt to be entirely white: it is shaped as a seagull; in the book of Deuteronomy it is said that it must not be eaten; that very dear is the bird. And Physiologus says that the caladrius ought to be in the court of a king, and about one thing is learned. If a man should have his eyes running or rolling the caladrius has such a nature that it can cure the eyes by the divine virtue which it possesses; it is in its thigh, if one applies it; such virtue has the thigh of the caladrius. The bird has a great bone in its thigh; if the man who is blind has the marrow of it, and will anoint his eyes, he will immediately recover (his sight).

Honorius d'Autun [12th century CE] (Speculum Ecclesiae, Druce translation): But if he (the sick man) is going to live, it turns and fixes its gaze intently upon him, / With wide open mouth it drinks, as it were, his sickness out of him, / And flies up on high to the rays of the sun; / The sickness which has been drunk in sweats out of it, / The sick man exults in his recovery. / But turning his face to us, he (Christ) recalled us from death, / And himself bore our infirmities, submitting to the Cross; / And the bloody sweat dripped from him, / Then clothed in our flesh he rose into the highest heavens to the Father, / And granted Salvation for ever to all the faithful.

Suidas [12th century CE] (Lexicon, Druce translation): They say that this is a disease [jaundice] producing paleness, which arises from anger, so that it makes the eyes of those who are overpowered by it pale and sometimes black, like (the eyes) of kites, from which also it takes its name. They say too "that those who suffer from jaundice are easily cured by looking at a bird, the charadrius." The charadrius is a bird of such nature that if those who are suffering from jaundice look at it, as report goes, they more easily get rid of that disease. For which reason also the sellers (of the bird) hide it, lest those who are suffering from jaundice should be cured for nothing. "Why, he is hiding it: like a man with a charadrius to sell," as Hipponax says; whence has arisen the proverb: "Imitating the charadrius," said of those who hide anything. [quoting Euphronius]: Since the gaze of the charadrius alleviates the jaundice, the sellers of it conceal the bird, lest any man, before buying one, may look at it as he passes and get cured, and he adds, "Others, however, say that it is not those who look at the charadrius who are cured of the jaundice, but those who eat it."

Hugh of Fouilloy [12th century CE] (De avibus, Druce translation): About the charadrius or charadrus, a maritime bird. It may be clearly so named, because Theodorus Gaza calls it charadrius. Suidas (calls it) charadrus, who tells us that it is a maritime bird great and greedy, and possessed of such power that if those afflicted with jaundice gaze at it, they are freed (from their complaint), as Pliny has asserted about the bird (called) "icterus," perhaps the same and so called from the cures which it effects.

Alexander Neckam [13th century CE] (De laudibus divinae Sapientiae, Druce translation): With propitious gaze the caladrius looks at the sick man, / When Lachesis twists her thread with favouring hand. / With eyes averted it raises a warning cry of sorrow / As often as it perceives the day of death approaching. / Its flesh restores the bright keenness of vision which has grown dim. / The colour of its wings is said to be milk-white.

British LibraryMS Royal 12 F xiii [13th century CE] (Rochester Bestiary, Druce translation): The Caladrius or Caradrius, as the Natural Philosopher [Physiologus] says, is all white like the swan, and has a long neck. The dung of its inside cures blindness [caliginem oculorum]. This bird is found in the courts of kings. If anyone is ill, by means of this caladrius it can be found out if he will live or die. For if the man is destined to die, it turns its face away from him, and by this sign people know that he is going to die. If he is destined to live, it directs itself towards his face, and as though it would take all the illness of the man upon itself, it flies into the air towards the sun, burning up as it were his infirmity and dispersing it; and so the sick man is cured. The caladrius is a type of our Saviour. For he is all white, because he has committed no sin, neither is there any guile found in his mouth. But Christ coming down from heaven turned his face away from the Jews, because of their unbelief, and turned to us Gentiles, bearing our infirmities. ... But the caladrius is reckoned, in Leviticus, among the unclean birds which are forbidden to be eaten and imitated. And yet it signifies Christ. For it is unclean by virtue of that property of its nature through which it, having a long neck, seeks food for itself out of the very bowels of the earth. And therefore through that property it typifies the contemplative man, who has an appearance of religion, who reads about heavenly things, but whose life is earthly, who in this matter should not be copied. But by that property which it has, of turning itself away from those who are about to die, and conversely towards those who will live, and flying upwards towards the sun, it signifies Christ; just as the lion and eagle, though they are unclean according to the law, yet are types of Christ by reason of some quality of their own. For the lion is king of beasts, and the eagle king of flying fowl, and Christ is king of all the faithful.

British LibrarySloane MS 278 [13th century CE] (Aviarium / Dicta Chrysostomi, Druce translation): If (the sick man) is destined to get better and be cured, the caladrius addresses itself intently to him, and approaching, puts its beak upon the man's mouth, and by its breathing draws out all the man's sickness into itself, and flying into the air towards the sun, burns up his sickness, and disperses it, and the sick man is cured.

British LibraryRoyal MS 19 D. i [14th century CE] (History of Alexander the Great, Druce translation): From there they went to the palace of king Xerxes. And Alexander found in this palace many marvels, and among other things he found birds of the size of doves which are called "salandres," which prophesy about a sick person, if he is going to die or not, or to live. For if it so happens that it looks at the sick man in the face, he must live, and if it turns the other way he will surely die. These birds, according to certain wise philosophers, have received this virtue from our Lord, that in looking as they do they receive into themselves the illness of the sick man. And they carry it on high to the fire which is in the air, to the fourth element which consumes all sicknesses.