In September and October I try to get out in the yard before dawn on good migration nights and listen for nocturnal migrants passing over. We have a decent spot with fairly low noise from traffic if the wind is light and north-westerly or northerly. The winds were north-easterly last night and I didn't expect anything much so I wasn't planning on it today, but at 4AM I was awakened by a female Great Horned Owl calling in the yard and I knew I was not going back to sleep. The Horned was doing some of the species' alternate calls that I find fascinating, an almost urgent version of the normal song but with an emphatic second to last note and with the nasal "Awnk" note also thrown in at times. Still awake I went out about 5:30 and listened for migrants passing over and was surprised at how many thrushes I heard, especially because radar had looked unpromising in the early hours. I heard about 40 thrushes in thirty minutes, which were mainly Swainson's but including one Gray-cheeked and one Gray-cheeked/Bicknell's type. Counting thrushes can be problematic because they call about every 4 to 6 seconds and it can be easy to over-count, especially since there are often more than one calling at the same time. I try to be conservative and I suspect I under count, but I prefer that to over-counting. The best surprise of the night however was an American Bittern which called once as it passed by. A new yard bird for us, which isn't surprising since you don't get many American Bitterns in the yard when you live on top of a hill next to a dairy farm! Dave Provencher Preston