I have seen it go both ways....The "Beep" (from focus lock) has brought them to my blind. the shutter action ,has never changed the birds actions (For me ).
BUT I also have had the "Beep" scare the crap out-of the birds ,and cause them to flush !
I turn off the beep ,and use a mouth call to get them as close as I can, to my blind. sometimes that is as close as 2 feet . once they are with in 20 feet I start photographing .The shutter action (As far as I have seen) doesn't have any affect.....regaurdless if I'm photographing Turkeys ,Ducks Or Deer...heck any game for that matter . BTW I have a D90 Nikon ,And A Cannon T2i ,same goes for both cameras .