In Cinderella there are a number of scenes where a dove flies on the set.... from the Fairy Godmother's hand upstage to a tree next to Cinderella downstage. Also, flies on set and lands on a tree. Any suggestions on how to do this?
We did a similar effect for the 2007 Pageant of the Masters. In our case one of the sculptures we did was of Peter Pan. As a part of this piece, we had Tinkerbell flying around over the audience. Tinkerbell was a small battery powered halogen lamp. This effect required some rather intricate rigging, which is a forbidden subject on CB. This effect required three operators and some very specific choreography for those operators.
I imagine that your dove effect would require a similar set-up. We brought in a professional rigging company to set up our effect. Unfortunately I don't know whoe it was that we brought in. Maybe someone on this site will be able to point you in the direction of someone qualified to rig your dove.
Progection could do the same effect, the trick would be having a medium to progect on, i have seen it done in some shows where the image was progected onto scenery that was really close to the actors (The effect wont really work if you progect onto say the rear cyc and the actor was at the front)
What about putting a small fake dove onto some tiny fishing line. Attach the line to somewhere high off stage and have the other end on the tree (lower). Let it slide down the line into position. If your audience is a typical distance away they'll never see the line.