Imagine Muggleborns having patronuses that represent something from Muggle culture that they feel protected by. A shy Hufflepuff with a Pikachu patronus. A Slytherin who’s really nervous because of all the stuff in the past and they’re Muggleborn but they cast a patronus and it’s one of the Game of Thrones dragons. A Gryffindor being the talk of the common room because of their Jaeger patronus. A Ravenclaw with a comic obsession finding out their patronus is the Hulk.
The birds were created by mistake. The jabberjays - all male - were initially created to eavesdrop on the rebels in the Dark Days, memorizing entire conversations and repeating them back at the Capitol. Once they were discovered, the rebels fed endless lies to the birds, and sent them back loaded with false information. After the lies were discovered, the Capitol closed the laboratories and the jabberjays were released into the wild, in the hope that they would die off. They did, eventually, but not before they passed on their genetic code to female mockingbirds. This was unforeseen, because no one expected them to have the brains to reproduce. The offspring were called mockingjays. (mockngj)