Sources : Falcon

Aelianus [170-230 CE] (On the Characteristics of Animals, Book 2, chapter 42): Falcons are excellent at fowling and are in no way inferior to eagles; they are by nature the tamest of birds and the most attached to man; in size they are as large as eagles. And I am told that in Thrace they even join with men in the pursuit of marsh-fowl. And this is how they do it. The men spread their nets and keep still while the falcons fly over them and scare the fowl and drive them into the circle of nets. For this the Thracians allot a portion of their catch to the falcons and find them trusty friends; if they do not do so, they at once deprive themselves of helpers. Now the full-grown falcon will fight both with a fox and with an eagle; with a vulture it frequently fights. But a falcon will never eat the heart, thereby presumably fulfilling some mystic rite. If a falcon sees the dead body of a man (so it is said), it always heaps earth upon the unburied corpse, though Solon laid no such injunction upon it, and will never touch the body. And it even refrains from drinking if a solitary man is engaged in leading off water into a channel, feeling sure that it will cause damage to the man who so labors if it purloins the water which he needs. But if several men are engaged in irrigating, it sees that the stream is abundant and takes its share from the loving-cup, so to speak, which they offer, and is glad to drink. - [Scholfield translation]

Isidore of Seville [7th century CE] (Etymologies, Book 12, 7:57): The capus is named in the language of Italy from ‘seizing’ (capere). We call this one the falcon (falco), because its talons are curved inward. - [Barney, Lewis, et. al. translation]

Gerald of Wales [c. 1146 – c. 1223] (Topographia Hibernica, Distinction 1, chapter 8): There are several kinds of falcons, both large and small, high bred, and kestrels; merlins [ineruli] also, small and summer birds, though sluggish at first when fat, afterwards swoop suddenly on their prey, and soaring on high in wide circles, pounce from above on the quarry, and having struck it and crushed it with the force of their breasts, pierce it and tear it to pieces with their extended claws. Their flight is so rapid and unwearied that, pursuing the bird which endeavors to escape, and flits from side to side, now high, now low, while all the spectators are filled with delight; no length of flight in the vast aerial amphitheater, no artifice of the fugitive, can save it from its relentless foe. - [Forester translation, 1863]

Thomas of Cantimpré [circa 1200-1272 CE] (Liber de natura rerum, Birds 5.44, 5.50): [Birds 5.44] Herodius, which is also called girfalus, as the gloss on Leviticus says in a place where unclean birds are forbidden, is called a girfalcus. As he says [i.e. Liber rerum],the bird is the most noble of all the noble birds. It is cerulean in color, but in the greater part of the body it shades to a white color beyond the chest and wings, where it imitates the blue color more evidently. This bird is so strong and great, as the gloss on Leviticus says, that it defeats and captures the eagle itself, which is the strongest bird. And it will fly with such courage, that when it has been released after five cranes or any other birds flying in the air, it does not stop chasing the birds until it has brought down all five one after the other to the ground. Now there is a dog trained for this purpose, which, by the falcon flying from above in the air and throwing down the birds, the dog suffocates and kills the birds thrown to the ground. As the Experimentator says, it eats raw meat but not preserved meat, but fresh. It ascends to a height and with a sudden descent it throws down its prey. In flying towards the prey it holds its legs to its chest and thus strikes the prey. If it does not catch the prey in the first attack, it rushes to the depths and reluctantly returns to the hunter because of annoyance. When it sees a prey, it shakes itself, and if it is fit to be caught, it knows. There is a certain kind of gyrfalcon which is known as sacred; and these are stronger. But they have a brown color. [Birds 5.50] There are seven kinds of falcons, as Aquila and Simachus and Theodotion say, who of course wrote a letter to Ptolemy the king of Egypt, in which, by his order, they treated of the noble birds, which we call raptors, according to what they could find in the ancient writings. It is also written in the same letter about the medicines of the said birds, which, for the sake of brevity, we have condensed into a concise language. There are eight kinds of falcons. The first, which is called the woolly, of which there are two kinds: one has a large head and beak, and feet like an eagle, which with great labor is enabled to catch birds; but in the second and third year of its qualification it excels in flying. But another kind of woolen is smaller in stature and considered by men to be inferior. The second type of falcon is called peregrinum [peregrine], which is capable of easy flight. The third type is called montanum [mountain], and it is therefore rougher and finer. The fourth kind is cerulean in its feet and legs, whence it received its name; this is considered noble in the first and second year, but in the third year the lowest. The fifth species, slender and long in disposition, is the most active in flight. The sixth kind is called supranicum, which has almost a resemblance to an eagle, except that it resembles a falcon in its feet and wings and eyes. The seventh genus is britannicum, 'British', and this holds the dominion of all birds of prey, so that neither a bird dares to catch a bird before it, nor any of the other birds dare to fly above it. This kind has thick feet, gnarled legs, cruel claws, a fiery appearance, terrible eyes, a large head and chest, and large sets of wings. Those who are able to fly very easily can fly a lot and for a long time. They like to feed very delicately and eat almost as much as an eagle. And we believe that this type of bird is called the aeriophilon, or commonly called aelion. The eighth type is that which is called herodius or commonly girfalcus [gyrfalcon]. This type is more common than the aelion type and is considered more expensive because of its control of food and life. [Birds 5.51] The falcon is the most noble bird: it flies most impetuously towards its prey, and is less cautious in keeping its guard. Therefore, when the falcon is to be directed at the prey, it is slowed down by its master, and the bird is not shown to him to be caught, unless it is first a little distanced, so that it may follow the prey with a controlled attack. On the other hand, when two falcons are relaxed together, they fly socially. One flies high, the other flies near the ground, that is to say, so that the one who flies high will attack the flying heron and knock it down by the impact, and the one who flies at the ground will receive the fall. There are two kinds of falcons: one lowly, which only takes a bird it has been accustomed to by much labor and effort; but the second is noble, which naturally catches the bird with little training. The first kind, which is considered cheaper, when it has driven a heron to the ground, and is about to catch it, the heron throws out of its mouth an eel or some other fish which it has lately devoured. Nor does the ignoble falcon delay to allow the captured heron to fly into the free air, and joyfully grasps the offered and stinking gift rather quickly. - [Badke translation/paraphrase]

Bartholomaeus Anglicus [13th century CE] (Liber de proprietatibus rerum, Book12.3; 12.20): [Book 12.3] As the Glose saith Super Deutro. 14. Alietus & a Fawcon is all one bird, which coveteth praye, and is right bolde and hardie, and assaileth birdes & foules, that be much more greater than they, & réeseth on them, and smiteth with breast and with féete. Some men meane, that Alietus is a little bird, and taketh other small birds. Thereof speaketh Auctour Aurora and saith. Obtinet exiguas Alietus corpore vires. Sunt & aves minimae, praeda cibusque suus. That is to saye, Alietus hath small vertues and strength of body: and small birds be his meate and his praye. And some men meane, that this bird assaileth onelye feeble Birdes and unmightie: and héereby it seemeth, that Alietus and a little Sparrow Hawke is all one, that is called a Musket in French, or els it is called, the Sperhawke. [Book 12.20] The Faulcon is called Herodius, and is a royall fowle, and desireth praye, and useth to sit on his hand that beareth him, and is a bolde birde and an hardye, as is the Gosehauke: and hath little flesh in comparison to his bodye, and hath many feathers: and therefore he is more lyght to flye. For in him is little thing that beareth downewarde, and much that beareth upward, as Gregory sayth. And therefore he is right lyke to the Estridge in boldnesse and strength: and also much like thereto in divers feathers and coulours. The Faulcon is full bolde and hardy, with most sharpest breast, & with strong clawes, & hurteth more his pray with rising theron with his breast, then with his bill, or with his clawes. And is so greate hearted, that if he fayle of his pray in the first flyght and réefe, in the second he taketh wreake on himselfe. And so if he be wilde, unneth that day he seeketh praye. And if hee be tame, as it were for shame he flyeth aboute in the ayre, and then unneth he commeth to his Lordes handes. For he holdeth himselfe overcome, & as it were put out of kind, if he taketh not the foule that he flyeth to, as Gregorie saith. This foule or bird is commonly called Falco, and Fulica also [fulica is the coot, not the falcon; Bartholomaeus confuses the two in what follows], as the Glose sayth Super Spalmum. And among all Birdes and Fowles, these Fowles have little affection, and take little héede of their Birdes, as it is said in Exameron. With the same office of businesse, that he feedeth his owne birds, with such service he taketh and féedeth the birds that the Eagle throweth out of her neast, and is unknowne to him. He flyeth and voideth carrion, and toucheth not stinking flesh, not in strong hunger: But he may well awaye with travaile, and absteineth and abideth till he maye finde covenable praye, which he séeketh, as Gregorye saith. - [Batman]