There's a minimum threshold, and I don't think crows would earn enough to end up paying it. But if they did… surely there's some mechanism for dealing with individuals who have the capacity to provide significant value to society (=¹ get paid a lot), but lack the capacity to do government paperwork.
Usually, that position is restricted to humans. Maybe there's a crow sufficiently competent at mayoral duties, but crows aren't great at abstract verbal communication via sentences; I doubt any crow would be good at the job. (Though if no crow is competent, why have laws restricting them from being eligible?)
It's probably up to the bank, and of course rather challenging for them to pay their income taxes as we all must ...