Following some of the advice received on this forum, I had my first successful search for screech owls last night! It was very exciting, the only time I have ever heard a wild screech owl was just by chance from the living room of my house last summer. To succeed in my search was very rewarding to say the least.
I began owling around 6:30 PM at a local patch with many rumors of owl records. My friend and I made four stops , about 10-15 minutes each, without having any luck. We would begin with Saw-whet owl and play call back recordings once every two minutes or so. After repeating this process about 3 times we would cycle through other species- screech then barred owl. On our fourth stop, and about an hour after the beginning of our adventure, we were getting slightly discouraged when out of the silence we heard a smooth, descending monotonic screech. It sounded quite a bit different then the several recordings we had been using, so both of us looked at eachother and asked, "what was that?". My gut was that it was a screech owl, but I was unsure. It just sounded like a painful squeel at first, but no more than 10 seconds later it was there again. The quiver in its voice was audible this time and I had no doubt anymore. It continued to call on and off for at least 5 minutes. And the best part, at one point both my friend and I clearly saw it fly directly over our heads.
We reached the marsh edge last, where we had two owl sightings without the use of playback recordings. Here we were playing yellow rail, black rail and Virginia rail calls, with Virginia being our only real hope. Anyhow we did not have any luck with rails.
In total, with at least 2 great horned owls calling in the background, a close range screech owl, a long-eared/short-eared sighting along the marsh edge and an unidentified large owl sp. in the same vicinity, this was one of the best birding nights of my life. Thanks for the contribution everyone!