I had a movie but it was too big for the DFMA. But I can confirm that, at least in 33d, cages "vanish" when flooded. Except, they're still there, they just don't show up visually nor when looking with k. The stocks screen will still list them and putting down an animal stockpile will make the dwarves grab them, which makes them reappear.
Here's a rough diagram of my set up:
code:
~~████████████████████████
~~~X.....‼........<<X>>█
~~~X..‼.....‼.....<<X>>█
~~████████████████████████
I got the cages down there by setting up 1x1 animal stockpiles, then removed the stockpiles. The stairs on the far right are a drain for the water, they just lead down to a large room. Open the left set of floodgates and the water fills the chamber, pushing the cages a few tiles. Once the cages stop moving, they disappear. They will reappear if they get pushed some more, or bump in to each other. Once the chamber was 7/7, I shut the left set of floodgates and scanned the chamber with k. No cages were listed in any of the tiles. Then I opened the right set to drain the chamber. One of the cages reappeared when the flow pushed it down the stairs, and I lost track of it from there. I went to the stocks screen and zoomed to one, it showed nothing there. Then I set up an animal stockpile upstairs, watched this area, and a dwarf went to the zoomed square and the cage reappeared in his hands. After a few moments, all the cages were back in the animal stockpile, so I didn't lose a single one.
Incidentally, I'm not sure that this is really a bug, but it seems really odd that empty cages go on an animal stockpile, rather than a furniture stockpile. I'm guessing this is because dwarves are too dumb to tell empty and full cages apart, so they both have to go on the same stockpile?
[Edit: Too many █'s makes the forum software despite showing up properly in previews...]
[ December 21, 2007: Message edited by: Nesoo ]