Harry climbed into the common room. Ron and Hermione were having a blazing Row.
"I can't believe you would cavort with the enemy," yelled Ron.
He stormed past her to the staircase, paused, and turned around.
"AVIS! OPPUGNO!" Ron bellowed. The birds shot towards Hermione like golden bullets, pecking and scratching at every available bit of flesh.
"Ow! Stop, please!" Hermione yelled. She screamed in pain as Ron shot a look of vindictive fury and shot up the stairs. Harry thought he could hear a sob.
Just trying to show why the canon bird scene in HBP is stupid.