Every September thousands of Vaux’s Swifts come to Portland. After spending their day eating bugs, the Swifts coalesce in Northwest Portland, flying in a giant undulating swirl in the sky above the school. Around sunset the swirl gets more compact, like a ground pepper tornado, and begins disappearing, measure by measure, down the chimney. On the lawn below hundreds of Portlanders stare mesmerized at the sky, from the comfort of lawn chairs and blankets. Boos erupt when opportunistic Peregrine falcons get lucky. The crowd cheers, however, when the predators are thwarted. Meanwhile unruly and oblivious children [are there any other kind?] scream and roll down the grassy hill.
Seriously, though, it’s a hell of a lot of fun. Read Heather’s excellent account of our first visit in 2008, and mine from 2009. Here’s a quick video Heather captured of the birds in action in 2009:
The Audobon Society of Portland maintains the Swift Watch webpage, which includes details on the best times to show up, explanations of the phenomena, and FAQs answering all your questions on the natural history of the phenomena, the bird counts, and sundry. Oregon Field Guide did a segment on the Vaux Swifts a decade ago, and there’s even a movie, called On The Wing.