Magpie's Nest
Magpie's are often attributed to collecting shiny objects, and having messy nests. As such, if I were to describe something as a magpie's nest, I would mean that it is a messy collection of various curious, shiny objects. This however seems slightly juxtaposed to more typical usage. Firstly, searching on the internet, I've found that the term is not as popular as I thought. Collins dictionary lists that "magpie" can be used as a term to describe a person who likes hoarding items of small value (ref), and other sources seem to put more emphasis on a "magpie's nest" being full of stolen objects.
Humorously enough, one study from Exeter University which looked at a small sample of eurasian magpies (pica pica), indicated that the the eurasian magpies didn't have any particular affinity to shiny objects, and in fact recorded a hesitancy to eat in the presence of shiny objects. The myth of magpies collecting shiny items is generally attributed to the popular 1821 opera La gazza ladra (The Thieving Magpie)
The magpie is supposed to be described on pages 666 to 672 in volume 3 of Historia animalium, a book printed in 1555 by Conard Gesser. I very much enjoy reading old books and what they have to say about things, but alas, I cannot read nor write Latin. Unfortunately, Topsell left out the birds in his "The History of Four-Footed Beasts and Serpents", which drew strongly on the works of Gesser. If you can translate, or know of a translation, I would be incredibly keen to hear from you. Please send me an email at magpies@intherain.cloud.