Oregon Swift Show

Oregon Swift Show

September 9, 2001

The elementary school furnace had been turned off, so children sat in their classrooms wearing winter clothing to stay warm.  A scene from an underdeveloped country?  No, this event takes place every spring and fall in the Chapman School in Portland, Oregon.  Why?  Because the school administration and the kids realize that if they ignite the furnace to warm the building, hundreds or maybe thousands of birds roosting in the furnace chimney might be killed.

It is one of the most spectacular bird displays we have seen.  Vaux’s Swifts spend the summer near the coast of the northwest USA, British Columbia, Canada, and Alaska.  In September, they begin to collect in certain places before they make their major migration into Central America and Venezuela for the winter.  One of their major collection sites is at the Chapman School, where they roost at night in a single, large chimney.

Pat and I had read about this display of swifts from the Portland Audubon website and decided to see it for ourselves.  We were instructed to arrive one hour before sunset.  A small crowd was already there when we arrived.  Most sat on blankets and some were picnicking.  A few were sharing a bottle of wine.  We chatted with the volunteers who provided brochures and detailed information about swift biology.  Then we sat on the grassy sidehill beside the school to observe the spectacle.  The weather was very mild, the sky was blue and Mt. St. Helens could be seen in the distance.  Kids played happily on the school ground below.  Before the first bird appeared, I felt a dog sniff the back of my shirt.  Then I felt a strange warmness spreading below my right shoulder.  “Pat,” I whispered, “did that dog pee on my back?”

“I can’t see anything,” she replied.

Then an embarrassed fellow came up behind me and said, “Sorry but my dog just wet your back.  I’ll be happy to pay for the cleaning bill or something.”

More amused than irritated, I replied, “Don’t worry about it.”  After all, the dog was just following his biological imperative.  His wolf ancestors marked their territories with urine and the instinct was probably genetically encoded in the little dog.  I muttered something about the dog not showing much respect to the visiting Texans, and we continued watching for swifts.

Soon the volunteer announced that he heard his first swift of the evening.  Scanning the sky with binoculars, I could see a couple of small, cigar-shaped, dark birds flying rapidly in the distance.  “They are one of the fastest birds in the world,” our volunteer claimed.  “They can fly over 100 mph when flying horizontally.”

Then, something like a gathering storm, the numbers of swifts began to grow and grow.  From our distant vantage point, they gave the appearance of winged flecks of black pepper caught in a big Texas whirlwind -- some so high that they were mere moving specks.  Lower birds would sometimes fly at the tall chimney as if to enter and then veer away at the last moment.  Almost exactly at sundown, the first swifts began to enter the chimney.  A cheer arose from the crowd.  By now there were thousands of swifts, but they could not all enter the chimney at once, so out of the cloud of swifts, the ones nearer the chimney flew in a large circle and whirl-pooled down into the opening.  By now there were an estimated 10,000 birds circling overhead -- not a good time to be looking skyward with your mouth open.  We received three direct hits on our car parked one block away.  By late-September there may be as many as 40,000 birds in this cloud, all entering the same chimney where, by clinging to each other, they may form up to four birds deep on the wall.

Suddenly, a larger bird appeared.  It flew with rapid wingbeats, fast and straight toward the top of the chimney where the swifts were congregated.  It passed through the funneling birds, but somehow the swifts avoided the attack.  As best we could tell in the dim evening light, the attacking bird was a Merlin Falcon.  Its wide wing base and falcon shape were the identifying clues.  It circled up and around through the swifts, but never seemed to capture any.  But the behavior of the swifts changed.  They stopped entering the chimney except for an occasional one or two.  The falcon circled a couple more times, then disappeared.  The swifts, possibly now terrorized by the falcon, also did not return.  The thousands that remained outside the chimney must have found some other chimney for the night.

This show takes place almost every sundown in September as the swifts congregate.  Then, about October 1, the whole group flies together to Central America and Venezuela.  I don’t believe that the Merlin is an official actor in the drama every night, but who knows?  It was certainly a show-stopper!

These interesting little swifts weight only 2/3 ounce and live during daylight hours in the air.  While flying, they catch insects for food, mate, drink and build nests.  Only at night do they stop flying and cling to the walls of a chimney or old growth snag to get a well-needed rest.

It was really a great show!  So good that David Attenborough is coming to photograph this event for a forthcoming TV series titled: “Nature in the City.”  Thus, you may be able to see it on TV and judge its merits for yourselves.  It was even worth suffering a little humorous humiliation by receiving a little dog “scent.”  As you watch the presentation in front of your TV, you should be safe from some canine mistaking you for a fireplug or being bombed by swift droppings, so enjoy the show!

Table of Contents: https://www.blogger.com/blog/post/edit/6813612681836200616/3382423676443906063?hl=en