Vaux's swifts are 4-inch, gray birds that migrate between Canada and Venezuela.

Every year, the birds make a pit stop at Agate Hall in Eugene, a popular spectacle for residents.

On a temperate, late summer evening filled with ambient tweets, Eugene residents watched thousands of birds form a tornado above the University of Oregon.

At least 150 Eugene and Springfield residents gathered the evening of Sept. 18 to watch thousands of Vaux's swifts dart across the sky — one of Eugene's longtime traditions — at the southeast corner of UO's campus. The spectacle culminates with the birds dramatically funneling into the defunct chimney of Agate Hall to roost for the night. Onlookers lounged in lawn chairs or on picnic blankets, craning their necks and using binoculars to get a better look at

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