Thousands of Vaux’s Swift birds swarmed a church in Salem, Oregon, then vanished down the building’s chimney in a wild scene captured on video this week.
At dusk one recent night, about 4,000 Vaux’s Swifts were seen in the video creating a huge, dark cloud over a church steeple before abruptly diving into its chimney to spend the night.
According to All About Birds, Vaux’s Swifts are small-bodied birds with long, very narrow swept-back wings that curve along both leading and trailing edges. They are larger than an Anna’s Hummingbird, but smaller than a Barn Swallow.
They are a “highly aerial species normally observed only during flight … often in flocks or pairs.” The site also explains, “Flocks preparing for migration roost in trees and also in chimneys, including in urban areas.”
Which is why the thousands of birds appeared in the evening sky over the Salem First United Methodist Church on Sunday.
A local university professor documented the unique phenomenon
“A swift’nado is spinning at Salem First United Methodist Church, and scores of neighbors, families, and @willamette_u students have gathered shoulder to shoulder at dusk, phones down, necks craned, watching 4,000+ Vaux’s Swifts pour into a brick chimney like smoke running in reverse,” area resident David P. Craig, a professor at Willamette University, wrote on Instagram alongside of several videos of the creepy scene. “Strangers are whispering ‘there they go’ to each other. That is what seasonal migration does when you give it an audience.”
“My students are out here counting birds and talking with anyone who wants to know why a chimney matters. The short answer: swifts evolved to sleep inside giant hollow old-growth trees, and as those disappeared, a shrinking handful of old unlined chimneys became their entire backup plan,” Craig continued.
“The birds also eat nothing but insects caught on the wing, so a roost this size is a nightly report card on the health of the local insect economy.
“Protect the chimneys, protect the bugs, keep the swifts. One ask: no drones. To a swift, a drone is a hawk, and a scattered flock may not make it into the roost before dark. The best seat is on the ground anyway.”