Birds do actually have regional "accents," or at least the calls of birds of the same species tend to vary based on region. I have no idea whether any of the ones Darryl mentions here are actually classifications for bird accents, but he's a bird, so he probably knows more about it than me. I do know that Upper Peninsula Michiganian is a thing, and that East St. Louis is a city in Illinois. Beyond that, I'm ignorant.