Isidore of Seville [7th century CE] (Etymologies, Book 12, 7.34; 12, 7.45): [Book 12, 7.34] The jackdaw [monedula] is a bird named as if the word were monetula [money] because whenever it finds gold it carries it off and hides it. [Book 12, 7.45] The jackdaw [graculus] is named for its garrulity [garrulitas]; not, as some people would have it, because they fly in flocks [gregatim], since it is quite clear that they are named for their call, for it is the most talkative species and importunate in its calls. - [Barney, Lewis, et. al. translation]

Thomas of Cantimpré [circa 1200-1272 CE] (Liber de natura rerum, Birds 5.62, 5.89): [Thomas describes the jackdaw under two names, graculus and monedula.] [Birds 5.62] The grackle [graculus] is a bird, which some mistakenly think is the same bird as the jay [garrulus]. There is a great difference between them, since the jay is distinguished by multiple colors of feathers, but the jackdaw is a bird of one color, and this is black throughout its body: for it is of the genus of the crow, although it is smaller in body. It likes to nest in high groves of trees, and this in such great numbers that often seven pairs of jackdaws build nests in one tree. For these birds sympathize with each other very well. The bird is very noisy, especially at the time of copulation, when the spring season incites the male to feed the female by the grace of love. The meat of its chicks is tender, and even more so if they are skinned. [Birds 5.89] The jackdaw, as Jacobus says, is called monedula as if the name meant "taking money" [monetam tollens] or "loving money" [monetam diligens]. For if it finds gold or silver, it steals it and hides it. This bird is black, but rather beautiful and pleasant. It imitates the voices of men perfectly well, when it has been trained as a chick. In the morning, when the sun rises, it is said to be more anxious to learn, and to retain it more tenaciously. As the Experimentator says, small pieces of meat excite an itch in it head; whence it also desires to be rubbed on the head. - [Badke translation/paraphrase]