This is the season when swifts are flocking prior to migration. Chimney Swifts are doing that here, and other species of swifts elsewhere. The birds roost in chimney, swarming around the opening before diving in. Two You Tube videos give you an idea of this spectacle. The first video was taken Friday night by local birder Curt Rawn at the old Oak Knoll Elementary School on Highway 55 in Plymouth (south side of highway, maybe half a mile east of I-494). You can see it at

http://www.youtube.com/watch?v=8adjITtMazA&NR=1&feature=fvwp

Another You Tube video, linked to Rahn's posting, shows a western species of swift -- Vaux's Swift -- entering a chimney to roost -- hundreds, maybe thousands of swifts. It's amazing. If you listen you can here oohing and aahing from spectators.

Saturday night marked the beginning of a swift census here in Minnesota. Observers are finding an active chimney, setting up shop at about sunset (say 8:30 p.m.) and counting the birds as they enter the chimney. This is a citizen science project sponsored by Audubon Minnesota. You can participate. There's an active chimney somewhere near you. For more information, go to

http://mn.audubon.org/birds-science-education/audubon-at-home/chimney-swift-conservation-project

Here are two swift photos. The first shows a Chimney Swift flying near the Wayzata West Middle School Friday morning. I'm certain the swifts in this small flock of about 15 birds are roosting in the school chimney. I was there Saturday night to observe and count, but arrived late, seeing only one bird fly down the chimney. I'll try again Sunday night. The second photo shows Chimney Swifts entering the chimney at the Oak Knoll school last year at about this date.