I plugged in my Sonic Super Ear? and listened in 5min periods at
about 30min intervals this evening for birds migrating over my
house. I recorded each call I heard without attempting to decide
whether it was a single bird making multiple call notes or
multiple birds:

2035-2040
no detections
2110-2115
Caspian Tern 2
Swainson's Thrush 3
Dendroica sp. 2
2145-2150
Dendroica sp 4
2220-2225
Caspian Tern 10+
Dendroica sp. 2
2245-2255
no detections

I also got to watch 4 RACOONS raiding the neighbors porch for
cat food.

--
Mike Patterson Alas, to wear the mantle of Galileo,
Astoria, OR it is not enough to be persecuted
celata at pacifier.com by an unkind establishment,
you must also be right.
---Robert Park
http://www.pacifier.com/~mpatters/bird/bird.html