City Cast Portland logo

What's the Deal with Portland's Swarming Swifts?

Posted on September 7, 2023   |   Updated on September 30, 2025

Rachel Monahan

dark birds above a blond brick chimney

Vaux's swifts swirling into the chimney at Chapman Elementary School, in Portland, Ore. (Sam May)

You know it’s September in Portland when 3,000 people, many of whom don’t ordinarily “put a bird” on their evening, go out to watch Vaux’s swifts at sunset.

The birds pass through Portland on their migration south and, each night in September, swarm like a tornado and then dive into an old chimney at Chapman Elementary School in Northwest. That’s where they spend the night huddled together.

(It’s also a heart-warming display of Portland’s nature lovers. My favorite moment last year was discovering a Portlander who’d brought their pet bird to watch the swifts.)

Today here are some intriguing facts (and mysteries) about the Vaux’s swifts:

  • The Chapman spot is, if not the biggest chimney the birds stop at along their migratory path, then one of the biggest. “There can be as many as 15 or 16,000 birds, on any single given night in the fall, that use the chimney,” says Joe Liebezeit, Portland Audubon’s assistant director of statewide conservation. “It could definitely impact their population and they'd have to find other places to roost” if the chimney were ever taken down.
  • The birds breed in the Pacific Northwest then travel into Central America for the winter.
  • Scientists don’t know why the swifts pick some chimneys and not others or why the Chapman chimney has remained the Portland stop on their migration south. There are some chimneys of similar size not far away, but they haven’t been used by as many birds or as consistently.
  • Why don’t other species need the spot? Many songbirds eat during the day and migrate at night. These swifts can eat as they travel. But at night they need to keep warm so they huddle together in the chimney. They also cluster together to stay out of the reaches of predators.
  • It’s also unknown which bird leads the flock. It’s not clear how they decide to start entering the chimney or who the decider is. But the U.S. military is interested in studying their movements. “There was a guy in the U.S. Army, who had gotten a grant to look at murmurations,” says Liebezeit. “There's development of drones is what I'm saying, for military purposes.”
sunset-colored sky with a swarm of black birds

Black birds swarm against the sunset-colored sky. (Devlyn)

When?

Every night this month (or until the swifts are gone). Arrive an hour before sunset.  It’s better viewing and more pleasant when the weather is dry. Which it’s supposed to be for the coming week.

The number of swifts usually peaks mid-September, but you may want to visit in the next week as the swifts this year started arriving a little early. (But it’s difficult for experts to predict the peaks.)

Where?

Chapman Elementary, specifically on the southwest side of the school.

Pro Tips

  • Bring a blanket and even a picnic dinner.
  • Bring your own cardboard to entertain the young (or the young-at-heart) with grass sledding as well.

Share article

Hey Portland

Stay connected to City Cast Portland and get ready to join the local conversation.

Can't subscribe? Turn off your ad blocker and try again.

Urban Almanac

See All
Urban AlmanacMarch 3

3 Oregon Wildflowers To Check Out This Spring

There are blooms all around us in spring. But here are three local wildflowers to seek out on your next adventure in nature.

white bloom with three petals
Urban AlmanacApril 7, 2025

Climate Change Poses Threat to Northwest Fish

Climate change is likely to compel all kinds of species migration that could lead to increased predation, competition and some localized...

A spawning redband trout from the Upper Klamath Basin next to the logs
Urban AlmanacMarch 20, 2025

Go Whale Watching This Coming Week in Oregon

It’s time for Oregon’s spring Whale Watch Week — Saturday, March 22 to Sunday March 30. In late March, the gray whales begin migrating up...

woman with binoculars stands at a window with a desk looking out at the ocean, with pink sky
Urban AlmanacMarch 6, 2025

What To Forage in Portland

There’s some good news for anyone curious about foraging for food (and fun) in Portland yards and wilderness areas. Almost all local weed...

green plants against the side of house, Portland, Oregon
Urban AlmanacDecember 19, 2024

Why Cross-Country Skiing Is Portland’s Best Winter Sport

If you’re looking for a way to stay active in the winter, consider cross-country skiing at one of the many great spots around Portland. I...

three people on skis
Urban AlmanacDecember 12, 2024

The Remote Destination in Oregon Where the Drive Is Worth the Final View

Summer Lake Hot Springs is one of those remote destinations where the journey is just as rewarding as the final destination.

dramatically lit dark sky with a building lit red outside with green light coming from windows
Urban AlmanacDecember 5, 2024

How and Where to Cut Your Own Christmas Tree in Portland

Oregon holds the distinction of being the top grower and exporter of Christmas trees in the country.

Two people drag a fir tree through a snowy area.
Urban AlmanacNovember 13, 2024

Here Are 11 Spots In Oregon You Must Explore This Winter

The Wallowa Mountains are a winter wonderland this time of year.

snowy rocky mountains

The latest in Portland

Food & DrinkOctober 5

The Best Fall Foods in Portland

A fall festival at Bauman's Farm apples at a Hood River orchard (Kiyokawa Family Orchards, ideally), and a Sauvie Island pumpkin patch (B...

A pulled pork sandwich, soup, and apple cider slushy at Sugarpine Drive-In.
The Weekly Wander by City Cast PortlandOctober 4

Side Quest: A Smile That Can’t Be Bleat

Need a mood boost? Portland's goats deliver. Here's where to visit, feed, and hang out with the city's most charming herds, from St. John...

A black and white goat stands elevated on a stone and wood tower outside of the Sellwood Goat House in Portland, Oregon.
Neighborhood GuidesOctober 4

Your Guide to Parkrose

Petting zoo, line dancing, and live music: Portland Fall Fest hits Rossi Farms on Oct. 4. Here’s how to make a day of it in Parkrose, plu...

A mural at 10721 NE Sandy Blvd. in Portland’s Parkrose neighborhood depicts farmers working in fields colored orange, red, and green. The blue-hued figures load yellow crates onto a blue truck.
Portland Life HacksOctober 2

Tips for a Better October 2026 in Portland

You know what’s coming: The next six months in Portland involve a lot of rain and colder weather, so let's get ready for it.

River with the steal bridge in the background, I-5 on the right side, downtown showing on right
Portland's BestOctober 1

What To Do in Portland in October 2026

Check out these classic October outings in Portland, including corn mazes, fall foliage viewing, and Halloween celebrations.

Tree leaves turning red.
Neighborhood GuidesSeptember 27

Your Guide to Kerns

When members of the Holy Trinity Greek Orthodox Cathedral moved into the large church at the corner of Northeast Glisan Street and 32nd A...

A street view from the corner of Northeast Glisan Street and Northeast 28th Avenue of the Apambichao Building, a cream and white colored Victorian apartment building that sits above Pambiche, a Cuban restaurant painted a deep blue.
Food & DrinkSeptember 27

Take a Tour of Franz Bakery in Portland

There are some things you knead to dough (sorry, seasonal allergies are the worst) about Franz Bakery, a fifth-generation, family-owned b...

Loaves of Franz bread tumble off of a conveyor belt at Franz Bakery in Portland, Oregon.
The Weekly Wander by City Cast PortlandSeptember 20

Side Quest: Go Big or Gourd Home

It’s almost pumpkin patch season on Sauvie Island, that time of year when caravans arrive in search of colorful squash to carve, and appl...

A pile of orange and green pumpkins at the entrance to The Pumpkin Patch on Sauvie Island. In the background, there’s a large red barn and farm store.