Amazing sound as always, I love this stuff. Have you heard the veery slowed down? It'll blow your mind. It comes about a minute or so in in this video http://nhpr.org/post/something-wild-eerie-sounding-veery I have that particular call in a field guide on my computer, but since it's copyrighted I can't post it slowed down here, but the one in the vid is almost exactly the same song. Sounds like a classical piece from the 18th century.
Really interesting! I have been searching for recordings of the snail radula for a couple of years, and this is the first one I have found. It would be nice to make recordings from different species of nsail and slug eating. Maybe one could rig a microphone pick-up to do it. The first challenge would of course be to make the creatures try and eat it. You were lucky indeed! Congratulations!