The flock of <a href="https://en.wikipedia.org/wiki/Vaux%27s_Swifts" class="extiw" title="en:Vaux's Swifts">Vaux's Swifts</a> swirling into a 1920s elementary school chimney to roost for the night.  These Vaux's Swifts (<i>Chaetura vauxi</i>) are quite selective about their roost during their annual migration from the Pacific Northwest to Central America.  They spend about four weeks in the Portland, Oregon area each autumn.
Kat+Sam
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