beta
Fun fact, carrier pigeons don't work like that!
They don't know how to get to any other location than "home", so what they'd do back in the olden days, is raise a couple of pigeons at the castle, put one in a cage when they traveled and then released him with the message, so the people at the castle would know they're fine. The pigeon would not be able to go back to the person who released him, so back and forth messages would be impossible.
The same goes for borrowing someone else's carrier pigeon, as they'd obviously just want to stay in their home and wouldn't even know where they're supposed to go. Unless the duke has such an army of pigeons, that he'd sent them in cages to random nobles so frequently that they wouldn't re-home, on the off chance that someone might want to message him, they'd likely be unable to do what they did this chapter.
This comment has been brought to you by the suspension of disbelief police. I can understand omegaverse shadow powers, but I draw the line at genius pigeons!