Board Thread:Off Topic/@comment-74.101.236.56-20170321065847/@comment-26397825-20170502214651

We've seen Qrow talk to a bird identical to him multiple times. In Higanbana she turned up directly after a bird identical to him showed himself to him. When he was poisoned, RNJR asked if there was anything else he had to tell them and he looked directly at a bird identical to him and paused before saying "not at the moment".

You're right, we haven't physically seen Raven turn into a bird on screen. But considering every time Qrow looks at a bird identical to him, Raven turns up or is withholding information about Raven, it is heavily implies by the writers.