Vaux’s Swifts, Chapman Elementary School, PDX
#152 of Things You Must Do in Portland
Every night in September at dusk, a very large flock of migrating birds, Vaux’s Swifts, gather to roost in the chimney of this elementary school. They are on their way to South America from Canada. The chimney is the bump in the middle of this photo. I found out about this event yesterday and decided to surprise Eric. I packed a picnic and and we headed out after work.
Here’s a quote about the birds:
“Historically, migrating swifts roosted in big hollow trees they found in Oregon’s
old growth forests, but now, thanks to logging and urban sprawl, most of those trees
are gone. In 1994, some adventurous swift scouted out new digs in the brick chimney atop
Chapman Elementary School. The little birds, 4-5” (“cigars with wings”), like the rough surfaces and
cracks in the bricks that give them lots of convenient toe holds,
plus the chimney is big enough to accommodate between 20,000 to 40,000 birds.”
As the days got cooler, the kids would wear extra coats to keep warm since they couldn’t use the heater. Eventually, the school had the chimney reinforced and installed gas heating so as not to disturb the birds.
“Fourteen years have gone by, and the swifts are still summer celebrities in Portland.
If you wander over to Chapman in the early evening, you’ll find a crowd of spectators
sitting on a grassy bank overlooking the school. Some bring their picnic suppers, some
bring champagne, many have binoculars and cameras. All ages come to watch the
swifts as they congregate and prepare to call it a day. At first, there are just a few of the little
birds circling the chimney, dipping close to the mouth of the chimney stack, then abruptly pulling up and
flying away to repeat the cycle. As more and more birds arrive, from a distance, they look like
a cloud of bees, wheeling round and round the chimney. Other birds – predators – also appear.
A hawk sits on the rim of the chimney, watching, waiting, then suddenly strikes and carries
off his unlucky prey. Occasionally, the tables are turned, and a gang of irate swifts attack the
hawk, driving him away, at least for a short time.
The flock grows and grows until the cloud of birds turns black, and still they circle. What are
they waiting for? Maybe they’re waiting for late arrivals? Maybe they are still catching insects
as they fly? (Swifts eat in the air, and during their migration, sleep midair, too). Maybe they’re
waiting for the air in the chimney to be the right temperature, or for the setting sunlight to fall
at a certain angle? The Audubon Society has put an information kiosk in the schoolyard; perhaps it
explains what finally triggers the birds’ descent.”
You can see the phenomenon here. The audio you hear in the video is not much different than what we experienced tonight. Kinda like a football game. There was a falcon who waiting until almost all the birds were in to pick off her snack. The crowd oohed and ahh’d as she was chased away at first, but then eventually got one.