Caladrius
A pure white bird who was deemed able to determine, by turning its head, whether a man would recover from mortal sickness. From the Aberdeen Bestiary (Aberdeen University Library MS 24), c. 1200:
Caladrius sicut dicit Phisiologus totus est albus nullam partem habens nigram. Cuius interior fimus oculorum caliginem curat. Hic in atriis regum invenitur. Siquis est in egritudine ex hoc caladrio cognoscitur, si vivat an moriatur. Si ergo est infirmitas hominis ad mortem, mox ut vi derit infirmum avertit faciem suam ab eo et omnes cognoscunt quia moriturus est. Si autem infirmitas eius pertinuerit ad vitam, intendit in faciem et assumit omnem egritudinem hominis intra se, et volat in aera contra solem, et comburit infirmitatem eius et dispergit eam, et sanatur infirmus.(The bird called caladrius, as Physiologus tells us, is white all over; it has no black parts. Its excrement cures cataract in the eyes. It is to be found in royal residences. If anyone is sick, he will learn from the caladrius if he is to live or die. If, therefore, a man’s illness is fatal, the caladrius will turn its head away from the sick man as soon as it sees him, and everyone knows the man is going to die. But if the man’s sickness is one from which he will recover, the bird looks him in the face and takes the entire illness upon itself; it flies up into the air, towards the sun, burns off the sickness and scatters it, and the sick man is cured)
The same entry provides an elucidation:
Caladrius habet personam salvatoris nostri. Totus est candidus dominus noster nullam habens nigredinem, qui peccatum non fecit nec inventus est dolus in ore eius. Veniens autem dominus de excelsis avertit faciem suam a Judeis propter incredulitatem illorum, et convertit se ad nos gentes tollens infirmitates nostras, et peccata nostra portans, exaltatus in lignum crucis et ascendens in altum captivam duxit captivitatem dedit dona hominibus. Sed et cotidie predictus caladrius infirmitates nostras visitat, mentem per confessionem considerat, et eos sanat, quibus gratiam penitendi prestat. Ab illis vero faciem avertit, quorum cor impenitens novit. Istos respuit, sed illos in quos faciem intendit, sanos reddit. (The caladrius represents our Saviour. Our Lord is pure white without a trace of black, ‘who did no sin, neither was guile found in his mouth’. The Lord, moreover, coming from on high, turned his face from the Jews, because they did not believe, and turned to us, Gentiles, taking away our weakness and carrying our sins; raised up on the wood of the cross and ascending on high, ‘he led captivity captive and gave gifts unto men’. Each day Christ, like the caladrius, attends us in our sickness, examines our mind when we confess, and heals those to whom he shows the grace of repentance. But he turns his face away from those whose heart he knows to be unrepentant. These he casts off; but those whom he turns his face, he makes whole again.)
For a discussion of other entries in English bestiaries, and the theme of anti-Semitism, see Debra Higgs Strickland, 'The Jews, Leviticus, and the Unclean in Medieval English Bestiaries', in Beyond the Yellow Badge: Anti-Judaism and Antisemitism in Medieval and Early Modern Visual Culture, ed. Mitchell B. Merback (Leiden: Brill, 2007), 203-232 (206-209). For the Aberdeen Bestiary, see http://www.abdn.ac.uk/bestiary/translat/56v.hti.