People will be flocking to Frank Wagner Elementary on Saturday for the annual Swift Night Out in Monroe.

It will be the ninth time the event has been held at the Wagner Elementary School chimney, where up to 25,000 Vaux’s Swifts have been found to roost in one night during their annual trek from Canada to Central America.

Residents from around the region come to rest on the lawn and witness one of the most significant stops in the migration of Monroe’s official bird.

“This is a wildlife spectacular,” said Vaux’s Happening project coordinator and researcher Larry Schwitters.

Factors such as heat or stormy weather can affect how many of the birds will show up on any given evening, Schwitters said. He jokes the chimney offers two-night accommodations for the swifts, which tend to stay at each site on their route for a couple of days on average.

Schwitters said in 2008 — the first year Swift Night Out was scheduled — about 14,000 of the birds flew in through the 31-inch-wide entrance. That is the highest count for the occasion so far.

That same night nearly 1,000 people came to watch the species funnel in. The last bird did two victory laps before taking the plunge, and the crowd cheered, he said.

About 6,000 birds showed up in 2009, but only 200 made it into the chimney before a hawk came along and scared the rest away, Schwitters said. Last year about 2,500 stopped in.

Schwitters said the world Vaux’s Swift population has been estimated to decrease by about 2 percent each year. Between 200,000 to 250,000 are alive today, he said.

For the past decade Schwitters has spent up to 12 hours a day, six months out of the year trying to bring attention to the birds.

“All birds are special — let me begin with these though,” he said.

The Vaux’s Swift is closely related to the North American Chimney Swift, of which there are about eight million in existence, Schwitters said. Their population is concentrated in the East Coast, he said.

Schwitters said Vaux’s Swifts come up the West Coast. They raise their young in the summer as far north as the Yukon and head back down to southern Mexico and Costa Rica in the fall, he said.

For a long time they were stopping in an old customs house in Sumas on the border of Canada, Schwitters said. They also used to stop at Sedro-Woolley and the Joint Base Lewis-McCord near DuPont.

The swifts can abandon a roost, Schwitters said. In Sedro-Woolley the birds have been absent for the past two years. It is believed the Merlin falcon — their primary predator — chased them away, he said.

Schwitters said research has shown the swifts “are a very friendly bird in a way.” A camera installed in the Frank Wagner chimney captures glimpses of their habits. There is only room for about 12,000 for them to cling to the rough surface. That means they must hang on each other when they are packed in; they don’t squirm, they don’t fight, he said.

Vaux’s Swifts don’t seem to be good at fluffing up to keep warm, which is the tactic used by other varieties. Instead, they share each other’s body heat and choose roosting and nesting locations that have been baking in the sun all day, he said.

“The more swifts that get in and share warmth the better off they are,” Schwitters said. “When they are swirling around the chimney, they are calling to all swifts, ‘Come share your body warmth with us.’ ”

Schwitters said the species has been flying into Monroe for about 30 years, according to some of the city’s old-timers. In 2007, local Audubon organizations were able to convince the Monroe School District not to tear down the decommissioned Frank Wagner chimney, he said.

Instead, $100,000 was secured so the school district could earthquake proof the structure, Schwitters said. He also put predator deterrents around the entrance to protect the swifts from crows and hawks.

Pilchuck Audubon Society president Cindy Easterson said regional and local partners watched the birds closely for a year before the first event was finally put on. Data drawn from those initial counts proved how crucial the roost site is for the species. It was then that different groups engaged the Monroe community in hopes of preserving the spot, she said.

The city has embraced the swifts ever since.

In 2016, they were named Monroe’s official bird. In January, Sultan artist Kevin Pettelle’s “Wagner Swifts” sculpture was set up in the downtown corridor. In August, Mayor Geoffrey Thomas signed an official proclamation naming Sept. 9 as this year’s Swift Night Out.

The Downtown Monroe Association will start fundraising for about 25 replicas of the stainless steel models represented in Pettelle’s installation during the event, Easterson said. Each one will be sponsored by a resident and named for a significant figure in Monroe’s history. They will be posted around downtown for members to seek out as an activity, she said.

A spaghetti feed will also be held at $6.50 a plate.

Schwitters will speak about the swifts, and informational videos will be shown throughout the evening. Activities start at 4 p.m.

Easterson said the 2017 event almost didn’t happen, but the Monroe Arts Council came to the call by offering the newly remodeled Frank Wagner Performing Arts Center as a space to set up the programs. It took the pressure off the school district and eliminated the expense of renting outdoor speakers and other equipment, she said. 

Even though there is no guarantee how many birds will attend that evening, every year “some sort of amazing thing happens,” Easterson said. Last year there weren’t as many swifts, but everyone witnessed a predator take out one in flight. It was sad to watch, she said. 

“But, it really emphasized the challenges these tiny little birds have on this migration they have been on,” Easterson said.

She said the situation also illustrated how important it is to preserve roosting sites like the one at Frank Wagner. The flock takes a tough journey each year. Maintaining a place for them to rest is one way for everyone to help make the trip a little easier, she said.