Vaux’s swifts are small, migratory birds that travel from their breeding grounds in the Pacific Northwest to Central and South American each fall, roosting in chimneys and hollowed-out trees along the way. For a few weeks in September, huge flocks of the birds have spiraled into the chimney of Chapman Elementary in Northwest Portland. The nightly display has entertained crowds for decades, but as of last year, the birds appear to have abandoned the chimney. 

Joe Liebezeit is the statewide conservation director for the Bird Alliance of Oregon. He joins us to talk about why the birds might be moving and what to expect from the swifts this year.