Roach joins the crew...
Geralt found the parrot looking very depressed in a Novigrad shop window and couldn't stop himself from rescuing her. He couldn't help himself. He loved animals. He hated to see them caged and in distress.
Which this bird clearly was. She needed him.
So he took her back to the ship and let her roam freely in his cabin and eventually the deck. Jaskier took a liking to her of course and frowned when Geralt said her name was Roach. "That's a type of bug. She eats bugs, Geralt. It's just mean."
"It's a bird. She doesn't care what she's called so long as she's fed and able to roam."
"Names are important."
Jaskier spent an unusual amount of time with the bird for a week or so after that, petting her and giving her little pieces of dried fruit. Geralt grew suspicous.
Apparently he had good reason to feel that way.
One day as he was steering them away from the coast, Roach flew up and landed on his shoulder. It wasn't an uncommon occurrence; Geralt got the feeling that she liked purveying her crew from such a high vantage point. Everyone spoiled her silly and she kept a mother bird's eye on them in return.
It was normal until she turned her little head in his direction and squawked a singular word. A word so clear and bright that nobody but Jaskier could have taught her how to say it.
"Bitch."
Jaskier was giggling like mad from down on the main deck. He pointed at Geralt's shocked expression and bent nearly in half with the force of his next laugh. "Names are important," he wheezed.
(@limrx you were right about the parrot thing)