38 birds flying over and making noise

OK, I would like to start by saying I'm not [necessarily] looking for someone to just hand me a script here - just point me in the right direction (if there is one?).

This is a bit of a complex problem... I was looking initially into the "swarm" script, but I really sort of need the bird(s) to disappear after they fly over. Sort of the way I see this happening (whether or not this is possible, I have no idea... But I've learned from you crazy geniuses that almost anything is possible!) is that you can enter the area (maybe hit a switch or a button of some sort? Not necessary, but maybe a nice feature...) and the first species of bird will be seen overhead - slowly floating by. You'll click on the bird, get a notecard, and while it flies, you can hear its call. Once it is beyond the borders of the forest area, the bird (as I see it, probably just a texture with an alpha channel) will disappear and the next species will begin to fly over, taking the same actions as the first, and so on for 38 species. (I know...) Another way this could work is, rather than randomizing them, get a menu with numbers 1-38 (or 1-10 with a "next" button... whatever...) and when clicked, the bird flies over and makes its call. I have no idea if this is possible at all, because I suppose it sort of involves rezzing an object at the push of a button with a script on that object - OR - changing the texture of an object? I don't know...

If anyone could just get me started - give me some suggestions on where to go with this...

you wont be able to use particles as you want something clickable, unless you did it with a large transparent prim in the same general area (to capture your clicks) which might not be such a bad idea but they would have no animated movement. the drawback is that the are that the birds fly would always be clickable. (some limits could be applied)

you could do the entire flock as a temp on rez linked object, and have it move on it's own from the rezzor, with the clickable script in the flock. more movement options, but also more scripting, and a seperate rezzor

individual birds could be done, but that's seperate scripts and rezzes for each bird in the flock... likely to be lag inducing, nevermind issues with that many rezzes, possible, not something I'd reccommend.

Just a random (and probably not ve y good) thought, how about a mega prim with an animated texture, Phanton when no birds are flying (to make it hard to click), non phantome when we have birds. (Just the first idea that comes to mind )