Sources : Cuckoo
Aristotle [ca. 350 BCE] (De animalibus Book 9, chapter 20.1-2): The cuckoo, as it has been already observed, makes no nest, but lays its eggs in the nests of other birds, especially in that of the phaps, and in those of the sparrow and lark on the ground, and in the nest of the chloris in trees. It lays one egg, upon which it does not sit, but the bird in whose nest it lays both hatches the egg and nurses the young bird; and, as they say, when the young cuckoo grows, it ejects the other young birds, which thus perish. ... The cuckoo appears to act prudently in thus depositing her egg; for it is conscious of its own timidity, and that it cannot defend its young, and therefore places them under the protection of another bird, in order that they may be preserved; for this bird is very cowardly, and when it is pecked by even small birds, it flies away from them. - [Cresswell translation, 1887]
Aelianus [170-230 CE] (On the Characteristics of Animals, Book 3, chapter 30): The cuckoo is extremely clever and most adroit at devising ingenious solutions to difficulties. For the bird is conscious that it cannot brood and hatch eggs because of the cold nature of its bodily constitution, so they say. Therefore, when it lays its eggs, it neither builds itself a nest nor nurses its young, but watches until birds that have nestlings are flown and abroad, enters the strange lodging, and there lays its eggs. ... And if the nests are empty, it will not go near them, but if they contain eggs, then it mixes its own with them. But if the eggs of the other bird are numerous, it rolls them out and destroys them and leaves its own behind, their resemblance making it impossible to know them apart and detect them. And the aforesaid birds hatch the eggs which are none of theirs. But when the cuckoo's young have grown strong and are conscious of their bastardy, they fly away and resort to their parent. For directly they are fledged they are recognised as alien and are grievously ill-treated. - [Scholfield translation]
Isidore of Seville [7th century CE] (Etymologies, Book 12, 7:67): The cuckoo (tucus) is named from its call. They arrive at a fixed time, riding in the shoulders of kites, because their flight is short and weak; in this way they do not grow tired in the long spaces of the air. Their saliva generates cicadas.