Chimney Swifts Converge on a Tower Near You

Updated 5.18: The back side of an abandoned school building doesn't seem an auspicious place to spot endangered wildlife, but check out that chimney. It changes everything.

In a recent letter to Town Topics, Princeton ecology professor Andy Dobson invited readers to witness one of nature's more remarkable annual phenomena, playing out in and above the tower of the old Valley Road School. From his letter:

In the half hour after sunset, several hundred swifts will be “turning and turning in a narrowing gyre” centered around the tower of old Valley Road School building behind Conte’s Pizza. It is quite a spectacular sight as the rapidly spinning circle of birds “know exactly where it leads, and you can watch them go ‘round and ‘round each time.” Suddenly, they will begin to drop down and disappear into the tower to roost for the night. “Wait ‘til you see half the things that haven’t happened yet.”

Andy encourages us to "come to the playing field on Valley Road and enjoy a truly remarkable local wildlife spectacle." 

"They will probably be there at dusk for the next couple of weeks while they pair up and locate nest sites on local tall buildings. The site is Princeton’s equivalent of the Serengeti wildebeest crossing the Mara River on their annual great migration."

His letter was published on May 8, and in typical fashion I didn't get myself over there to have a look until 9 days later. When I arrived, right at sundown, there was nothing to be seen--a golden opportunity for self-rebuke--but just as I began to leave, a high-pitched cheeping somewhere above pulled me back. They came, a few at first, then many, swooping down on the chimney only to veer away at the last possible moment. There is no clear choreography to their acrobatic flight, as they head off in all directions at great speed, sometimes in pairs but mostly on their own, each one's acrobatic flight describing a broad circle out across fields and rooftops, always to return to play yet again with the magnetic pull of the chimney. As the light fades, their gleeful independence ultimately yields to the collective impulse, drawing them down into the chimney's depths to spend the night.

   

Here's a link to Andy's wonderful letter. And here is a link to local writer Carolyn Jones' well researched article on our local chimney swifts and the longterm threat redevelopment of the Valley Road School site poses to their very specialized habitat. 

Andy's comparison of chimney swifts to the migration of the wildebeests that he studies in Africa has added meaning for those of us who have seen the university as often detached from the community of which it is a part. He recently began teaching a course called "Woods and Rivers of Princeton." The course gets students out exploring local nature, and has become so popular that this coming fall's course is triply over-subscribed. This valuing of the local is gratifying to see, and I like to think is part of a larger trend. 

Update, 5.31.24 Andy reports that "the swifts are still there, numbers declining as they pair up and locate nest sites. They should be back by the middle of August in even larger numbers with young of the year."