One of the signature biological events of the Pacific Northwest is the annual migration of the Vaux’s swift.  These tiny birds arrive from Central America in late April, spend the summer nesting in standing, hollow, dead trees, then disappear to the south again in September.  One of the unique features of the southward migration of Vaux’s swifts is that the birds gather in great numbers over a period of a few weeks in September, then leave in mass for points south (Mexico to Venezuela; a few overwinter in California).  The 1980 eruption of Mount St. Helens was considered a biological disaster for a huge swath of landscape, and huge hit for many species.  Not so the Vaux’s swift!  The eruption created a large patch of prime habitat for the Vaux’s swift.  The “scorch zone,” that part of the blast zone where the force of the lateral blast was diminished to the point that it could kill trees, but not so powerful as to be able to knock them down, killed a huge number of trees and left them as standing snags.  These snags formed a huge opportunity for the Vaux’s swift.  A gigantic swath of potential nesting habitat was created.  Unfortunately for the swifts, the majority of the “scorch zone” was harvested within three years of the blast.  Enough of this unique habitat was preserved within the National Volcanic Monument that the regional population of Vaux’s swifts was positively affected by the eruption. 

One of the main staging areas (gathering places) for Vaux’s swifts as they mass prior to southward migration is a huge old chimney at Chapman Elementary School in Portland (27^th & Pettygrove, NW).  Each day for the first couple of weeks of September more and more swifts arrive.  Swifts from Idaho, Montana, Washington and parts of Oregon congregate in this chimney, flying out during the day to forage and returning to the chimney at night to roost.  The evening return is so spectacular that it prompts an informal gathering of hundreds of people who thrill at the great masses of birds circling the chimney for an hour before entering the chimney in a tornado-like vortex at dusk.  I went last night to check on the progress and there were perhaps 8 to 10,000 swifts!  If you are anywhere within an hour of Portland and you can get to Chapman School between 7 PM and 8 PM in the next week it is well worth the effort.