Vaux’s swifts draw hundreds, sometimes thousands, of people to Northwest Portland’s Chapman Elementary each night as the birds roost in the school’s chimney from late August to early October.
FILE - Vaux's swifts funnel into the chimney at Chapman School in Portland, Ore., in this undated photo.
Nick Fisher / OPB
But this year, it looks like the birds have abandoned that roost early.
As recently as last Wednesday, volunteers counted more than 1,800 swifts taking part in the elaborate nightly routine. The next day, that number was down to less than 700. By Monday, volunteers did not see any of the birds at Chapman.
Joe Liebezeit with the Bird Alliance of Oregon said it’s still too early to tell why they’re not returning.
“We have noticed that there is predator activity. Cooper’s hawks and peregrine falcons commonly go there on most nights and they’ll often take out a swift,” he said. “We’ve noticed a little bit higher activity this year at the Chapman chimney, so that could be a factor.
Still, Liebezeit said they can’t be sure if the predators are the reason the birds left.
“There could be other queues inside the chimney that we don’t know about,” he said. “We need to go look in the chimney at some point, see if there are any obstructions in there.”
Related: In Portland, thousands gather to marvel at migrating birds’ nighttime routine
Vaux’s swifts are small birds that Liebezeit said look basically like “a cigar with wings.”
They migrate from Central and South America in the spring, and they nest in the Pacific Northwest.
“They do everything on the wing,” Liebezeit said. “They eat on the wing, they mate on the wing. The only thing they land to do is to nest and to roost, and typically they use chimneys.”
For at least 25 years, they’ve flocked to the chimney at Chapman. Over the years, crowds of up to 3,000 people have gathered to watch their nightly ritual. For 2023, the number of birds peaked Sept. 8, when volunteers counted more than 11,000 of them.
This year, the peak came Sept. 2, with more than 5,400 swifts. A week later that count was down to about 2,100. Then a week after that it was down to zero.
The birds are still roosting in other Portland chimneys, but Liebezeit cautioned that none of those other spots have the space, traffic control or parking capacity to accommodate the hundreds of people who often gather to watch the spectacular display.
He said at this point, it’s still hard to say whether any swifts will return to Chapman.
“We can try to speculate as much as we can,” he said. “But sometimes it’s hard to get in the little heads of those birds.”
For now, Bird Alliance volunteers will return every night, just in case they have some swifts to count.
Related: Vaux’s Swift roosting ritual at UO demonstrates adaptation, congregation — and sacrifice