What do the birds in the movie Psycho represent in Norman's life? Please someone help me with this question bc i have no clue what it is :(

There is the scene where Norman is talking to Marion in his parlor. Norman is trying to impress Marion but not doing a very good job. In the midst of discussing his taxidermy hobby, Hitchcock has a large stuffed owl filling the background of the frame. It seems to be looming over Marion: a symbolic reflection of how Norman, and ultimately Norman's mother, will swoop down on Marion a few frames later.