Bible (Job 39:13-18, New International Version): The wings of the ostrich flap joyfully, though they cannot compare with the wings and feathers of the stork. She lays her eggs on the ground and lets them warm in the sand, unmindful that a foot may crush them,that some wild animal may trample them. She treats her young harshly, as if they were not hers; she cares not that her labor was in vain, for God did not endow her with wisdom or give her a share of good sense. Yet when she spreads her feathers to run, she laughs at horse and rider.

Aesop's Fables [6th century BCE +] (The Ostrich; Perry 418) War broke out between all the beasts and the birds. When the ostrich was captured, she fooled both sides by being both a bird and a beast: she showed the birds her head, and the beasts her feet. - [ Gibbs translation]

Pliny the Elder [1st century CE] (Natural History, Book 10, 1; 11, 55): [Book 10, 1] The largest species [of birds], which almost belongs to the class of animals, is the ostrich of Africa or Ethiopia. exceeds the height and surpasses the speed of a mounted horseman, its wings being bestowed upon it merely as an assistance in running, but otherwise it is not a flying creature and does not rise from the earth. It has talons resembling a stag's hooves, which it uses as weapons; they are cloven in two, and are useful for grasping stones which when in flight it flings with its feet against its pursuers. Its capacity for digesting the objects that it swallows down indiscriminately is remarkable, but not less so is its stupidity in thinking that it is concealed when it has hidden its neck among bushes, in spite of the great height of the rest of its body. The eggs of the ostrich are extremely remarkable for their size; some people use them as vessels, and the feathers for adorning the crests and helmets of warriors. [Book 11, 55] The ostrich is the only bird with lashes on both eye-lids like a human being. - [Rackham translation]

Aelianus [170-230 CE] (On the Characteristics of Animals, Book 2, chapter 27): The Ostrich is covered with thick feathers, but its nature does not permit it to rise from the ground and mount aloft into the sky. Yet its speed is very great, and when it spreads its wings on either side, the wind meeting them causes them to belly like sails. [Book 4, chapter 37] Although the ostrich lays a number of eggs it does not hatch all of them but sets aside the sterile ones and sits upon those that are fertile; and from these it hatches its young, giving them the other, rejected eggs to eat. And if one chases the ostrich it does not venture to fly but spreads its wings and runs. And if it is in danger of being captured it slings the stones that come in its way backwards with its feet. - [Scholfield translation]

Isidore of Seville [7th century CE] (Etymologies, Book 12, 7:20): The ostrich [struthio] is named with a Greek term; this animal is seen to have feathers like a bird, but it does not rise above the ground. It neglects to incubate its eggs, but the abandoned eggs are brought to life by the warmth of the earth alone. - [Barney, Lewis, et. al. translation]

Thomas of Cantimpré [circa 1200-1272 CE] (Liber de natura rerum, Birds 5.110): The ostrich is a bird which in Greek is called assida; it is also called a camelon, because it has feet like a camel. When the time comes for this bird to lay its eggs, it raises its eyes to the sky to see if the star Virgilia has ascended. For it does not lay its eggs on the ground unless the star has risen. And this is the reason: for in the summer season, when the harvests are in bloom, around the month of July, the star Virgilia rises in the sky, and at that time the ostrich digs in the ground and there she lays her eggs and covers them with sand. Covering them, she descends from the place, and soon after laying her eggs, forgets them, and returns no more to them. For she is by nature forgetful. And therefore in the warm season she lays her eggs and covers them with sand, so that it is as if she was sitting and nurturing, and the calmness of the time and the temperature of the air seem to provide for her. ... Why, then, does the ostrich bury its eggs in the sand, unlike other birds, and nurture them with sight alone? Solution: Every generation of things needs a double beginning, a material and efficient cause. Now the material cause is matter, from which matter derives its being, heat being the efficient cause. For heat corrupts, digests, and transforms it into a species. But matter is complex: gross, average, and fine. What matter requires, then, is heat. If, therefore, the matter be subtle, it can be changed by weak heat, as we see in the hen's egg, which, because it is subtle in substance, is fostered by slight heat, so that an animal may be born from it. Wherefore the females cherish them in their bosoms. But the egg of the ostrich has the thickest substance, and therefore it needs the strongest heat. But the animal from which the egg comes has hard, nay, very hard flesh, and is a very hot animal, and this shows the effects of the matter, because it also digests iron. From this it follows that the ostrich wraps the eggs in sand, so that they are more warmed by the heat of the sand. But she concentrates on it by sight, as the visible heat of the spirit, which is potentially hot in her, because it proceeds from the hottest animal. Thus the air which surrounds it is heated. By virtue of heat, the grossest substance, dissolved and corrupted by the movement of generation, is procreated from that animal on which it rests by power. This bird has the wings of a heron and a hawk, but it is slow to fly. It eats iron. These birds, as Aristotle says, are almost like beasts. For although they have wings, they never use them in flight, because they are never raised from the ground. The form of its wings are thin and its feathers are like hairs. The Experimentator says that the ostrich has upper eyelids. Part of its head is different, and is close to the neck. It raises its wings as it runs. It eats and digests iron, because it is very hot by nature. It by nature hates the horse and pursues it in a strange way. But the horse fears and hates the ostrich to such an extent that it does not dare to see one. Under the wings it has a small bone with which it pricks itself in the side and shakes when provoked to anger. But it signifies those who are provoked to anger by a light word, provoking the devil to rise up for revenge. These birds run so fast on the ground that they overtake the horses with speed. Their hooves have bifurcations to catch stones, which they throw in flight against their pursuers. Their stupidity is so great, that when they hide their necks in a bush, they believe that the rest of their body is hidden. Their eggs are large enough to be cut across for use as drinking vessels. The ostrich moults naturally, as Pliny says, and sheds its feathers in such a way that it remains almost naked. But it has a very strong skin, with which it protects itself from the coldness of its lack of feathers. It has a large and wide bone on the chest like a shield, and this was created for the protection of its large body. For it has a body almost as large as an ass of average stature. - [Badke translation/paraphrase]

Albertus Magnus [ca. 1200-1280 CE] (De animalibus, Book 23, 102): Ostrich, though it is a denizen of the desert wastes of Libya, has often been seen in our part of the world. As a young bird it has a grayish coloration and its body is completely feathered, though the plumage is not rich and full. From its second year onwards, it gradually loses the feathers on its thighs, neck and head until it appears quite naked. In spite of this loss it is protected from the cold by its tough skin; meanwhile, its dorsal feathers become very dark and serve as a woolly covering. The ostrich has ponderous hips and fleshy, white-skinned legs which terminate in two-toed feet, like a camel. Hence, the bird is called "cameleon" by some of the Greeks and "asida" by others. It may reach a height of five or six feet, measured from footpads to dorsum. In addition, it has an extremely long neck, a head resembling that of a goose, and a relatively small beak in comparison to the size of its body. There is an anecdote that this bird can eat and digest iron, but I have been unable to corroborate its truth, for on a number of occasions I have offered pieces of iron to several ostriches but they refused to eat them. However, they avidly gobbled up some large dried bones that had been broken into short lengths, as well as some pebbles. Proverbially, the ostrich is a dimwitted bird that lacks any talent for flying. Nonetheless, it can run at high speed with its wings partly outstretched. On the inner angles of its wings’ elbow joints are sharp spicules with which it slashes at enemies within reach of its leaping attack. The ostrich lays its eggs during the month of July, burying them in the sand where they hatch from the heat of the sun, in the same way as the eggs of many other animals. Since it is unable to effectively brood on the eggs because of its bare-skinned body, it does not attend to them on a regular basis. But intermittently it guards the eggs and stands watch over the site where they were deposited. This trait has given rise to the false notion that the ostrich hatches its eggs by the visual power of its gaze. These are my personal observations of the ostrich, which to me seems not so much a bird, as a cross between a walking and flying animal. - [Scanlan]

Guillaume le Clerc [ca. 1210 CE] (Bestiaire, Chapter 31): I shall not refrain from telling you / Of the nature of the ostrich. / It is a wonderful bird / Which by nature is forgetful. / They call it assida in hebrew / And camelos is its name in greek. / It has feet like a camel. / Its nature astonishes me, / For it has feathers and great wings, / And yet at no time flies. / At the season when it lays, / It lays its eggs in the sand / And leaves them there and forgets, / And mark that it does not lay / Except about June in summer time. / When it has gazed its due time / And sees rising in the sky / A star which shines brightly, / Which star has the name Virgilia, / Then it lays at that time / And buries its eggs in the sand / And neither hatches nor disturbs them more. / To its eggs it never returns. / Right on the star its attention is, / And it forgets and leaves its eggs. / But God, who made all the world, / Helps them in such a way / That in the sand and drift-sand, / By the air which is soft and mild / And at evening and morning time / Is serene and favourable, / In the sand and in the dust / The eggs grow and make little birds; / It is one of the miracles of the world. - [Druce translation]

Bartholomaeus Anglicus [13th century CE] (Liber de proprietatibus rerum, Book12.33): THE Estridge is called Strucio, and hath that name of a word of Gréeke, as Isidore saith. For that he hath a bodie as a beast, & fethers as a foule: and also he hath two féete, and a bill as a foule: but for weight and heavinesse of body be flieth not with foules in the aire. She laieth egges as other foules do, but she neglecteth to brood her egges, she which egges be raken in gravel, and birds be brought forth by heat & nourishing of the dust, as Isid[ore] saith. And Aristotle speaketh of the Strucio, and saith, that the Strucio in making is like to a foule, and in some point he is like to a foure footed beast. For hée flieth not up into the aire; for his wings be not covenable to flight, but in the making therof is thin, as the making of her selfe, & for he is some deale shape as a bird he hath many fethers in the neather part of the body, & hath two féete as a foule, & is clove footed as a foure footed beast: and the cause thereof is, for by the greatnesse of his body, he is likned to a foure footed beast, and not to a foule, and is so hot, that he swalloweth and defieth and wasteth yron. And Avicen[na] saith, kinde that is wise and ware in all thing, graunteth to the Strucio a propertie to lay greatest egges and hardest of shell, that being occupied about the generation of them, heat may be temperate; for if the heat should be too vehement, it shoulde be cause why he should die the sooner. Other properties of the Estridge Gre[gory] toucheth super Job. 29. where it is sayde, that fethers of the Strucio be like in colour to the fethers of ye gentle Fawlcon, but not in vertue: the fethers have the likenesse, but he lacketh swiftnesse of flight. He spreadeth out his wings to flie, but yet he riseth not up from the earth: He is clothed with thinne fethers, & made heavy with a great body. And when the time is come that they shall laye egges, they heave up their eyes and behold the stars that be called Virgilie or Pliades: for they laye no Egges but when the constellation ariseth and is séene. And about ye month of June, when they sée those stars, theyd digge in gravell and laye there their egges, and cover and hide them with sande. And when they have lefte them there, they forget anone where they layed them, and come never againe thereto. But the gravel is chased with the heat of the Sunne, and heateth the Egges that be hidde, and bréedeth birds therein, and bringeth them foorth: And when the shell is broke, and birdes come out, then first the mother gathereth and nourisheth them: And the birde that shée despised in the Egge, shée knoweth when it is come out of the Egge. And therefore it is sayd to Job. Hée is made harde to his owne children, as though he were not his owne. Also the Estridge hateth the horse by kinde, and is so contrary to the horse, that he may not sée ye horse without feare. And if an horse come against him, he raiseth up his wings as it were against his enimye, and compelleth the horse to flie with beating of his wings. - [Batman]

Slavic Physiologus [15th - 16th century]: The struthiocamelon is a large bird. When he lays an egg, he lays it in water. Then he stands in the water and looks at his eggs. If he turns his eyes away [from the eggs], they will become addled. When he wants to sleep, he sleeps with one eye and looks with the other. Because there is another creature that resembles a snake and is fifty elbows long. When it sees that the struthiocamelon has laid eggs, this snake comes and watches. The moment the struthiocamelon turns his eyes away [from his eggs] to fall asleep over them, the eggs will become addled. The aspide stays here for forty days until the struthiocamelon raises [his brood]. - [Stoykova, English translation by Mladenova and Stoykov]