Did I miss this?
How was it this year?
http://riverside-avondale.blogspot.com/2009/09/birds-are-back-in-town.html
Really cool. I knew there were more birds than usual outside. Had no idea what it was. How'd you find that article..it was three years old!?
I remember going a few years ago and it is fascinating and quite the spectacle. It looks like a tornado of birds as they shoot down that chimney.
Chimney Swifts, not sparrows. We have some that are resident here year round, but lots of others that are migrating to South America. They eat bugs which are in short supply when there is snow on the ground so they follow warm weather.
Look up right now and you will see dozens of them hawking high above Riverside. At night they go into chimneys to roost away from the owls. They look like flying cigars.