Aristotle [ca. 350 BCE] (De animalibus Book 9, chapter 16.1): The hoopoe generally makes its nest of human ordure. - [Cresswell translation, 1887]

Pliny the Elder [1st century CE] (Natural History, Book 10, 44): The hoopoe also changes its appearance, as the poet Aeschylus records ; it is moreover a foul-feeding bird, noticeable for its flexible crest, which it draws together and raises up along the whole length of its head. - [Rackham translation]

Isidore of Seville [7th century CE] (Etymologies, Book 12, 7:66): The Greeks name the hoopoe [upupa] thus because it would settle on human waste, and feed on foul dung. It is a most loathsome bird, helmed with a protruding crest, always dwelling in tombs and human waste. Anyone who anoints himself with the blood of this bird and then goes to sleep will see demons suffocating him. - [Barney, Lewis, et. al. translation]

Thomas of Cantimpré [circa 1200-1272 CE] (Liber de natura rerum, Birds 5.119): Huppupa is a bird forbidden by law. As Isidore says, the bird is unclean, because it builds its nest in dung and prefers to dwell in stinking places. The bird, however, is very beautiful, and is capped with a protruding crest of feathers. In winter it is hidden and silent. Its voice is the only one as obnoxious as the cuckoo's. The aging parents shed their feathers in the nest among the already grown chicks, and are again fed by the chicks until they regain their strength and feathers. The Physiologus says that they have another kind of piety towards their parents. For when their parents have lost their sight in old age, the chicks by nature gather a well-known herb, and from there they anoint the blinded eyes of their parents, so that with the herb as an antidote their eyes may recover their clarity; and in this the piety of Thobie the younger is shown. Jacobus: If a man smears the temples of his head with the blood of the hoopoe before he sleeps, he will see himself in his dreams as if he were being suffocated by demons. The hoopoe's heart is good against evildoers and enchanters, but how this is done, the Experimentator does not write. - [Badke translation/paraphrase]

Bartholomaeus Anglicus [13th century CE] (Liber de proprietatibus rerum, Book12.37): The Lapwing is called Upupa among the Gréeks: for he eateth mans durt, and is nourished and fed ofte with doung, as Isidore sayth. For it is a bird most filthy and uncleane, and is copped on the head, & dwelleth alway in graves or in durt. And if a man annoint himselfe with her bloud when he goeth to sléepe, in his sléepe he shall sée féends busy to strangle & snare him: and her heart is good to evill doers, for in their evill dooing they use theyr heartes. Of this birde Philosophers tell, that when he ageth, so that he may neither sée nor flie, his birds pull away the féeble fethers, and annoint his eyen with juyce of hearbes, and hide him under their wings till his fethers bée growen: and so he is renued, and flyeth, and séeth cléerely, as Isidore saith. - [Batman]