Listening to migrating warblers

Many birds migrate at night and on a cloudy day with north wind birds fly at lower elevation and if you stand at right spot you can hear hundreds of them fly overhead. I was up on Mount Pleasant in Ithaca NY on 09/12/09 with others to listen to migrant birds. Every few seconds there were flight call notes given by birds. Initially, we heard mostly warblers from about 10.00 pm to 11.30 pm (at least that is when I was there) and then we started hearing thrushes and grosbeaks. I analyzed just one cut of 3.25 minutes recorded using my shotgun mic ME 67 with a minidisc recorder around 10.30 pm. In this cut I think, though I am not an expert there were 7 or 8 species of warblers along with veery, Swainson's thrushes etc. Based on the spectrograms of the calls, one of the calls matches very closely the spectrogram of Connecticut Warbler as show in Bill Evans' night flight call CD. I have posted the whole 3.25 minutes recording without filtering or tinkering along with few spectrograms in this movie I am posting here. I would appreciate comments if you have any. Have fun listening!


Meena