Healdsburg chimney a landmark roost for migrating swifts
An estimated 6,000 Vaux's Swifts enter a chimney on the campus of the Rio Lindo Academy in Healdsburg at sunset on Thursday evening. The birds have roosted in the 35-foot chimney over the past 21 years during their migration from the Pacific northwest to South America.
JOHN BURGESS/The Press DemocratPublished: Saturday, September 18, 2010 at 7:06 p.m.
Last Modified: Saturday, September 18, 2010 at 7:53 p.m.
As the last rosy glow of sunset vanished from the horizon, an injection of energy was palpable as thousands of birds mustered overhead.
Massing more tightly, the Vaux's Swifts picked up speed as they swarmed above an outer building of the Rio Lindo Adventist Academy east of Healdsburg's Fitch Mountain.
Then, one dove for the chimney, and the rest followed — an estimated 6,000 or so in a swirling throng that at times formed a spiraling vortex.
“They're going in! They're going in,” one onlooker shouted.
“It's like a tornado,” said another.
“Who gives the start signal?” said Brad Benson, director of alumni relations and fundraising for the Seventh Day Adventist school. He's also something of an expert on the small swifts that roost there during mid-migration each fall.
The swifts began using the chimney, located in a campus maintenance building, in 1989 — the first year a boiler in the building was no longer used to heat he water on campus, he said.
It is one of several landmark West Coast roosting stops used by the swifts as they travel south from seasonal mating habitats in Alaska, British Columbia and the Pacific Northwest to winter homes in Central and South America.
Arriving in waves, they're believed to stay for two to three days. They devour as many insects as possible and fatten up for the next leg of their trip, said retired Santa Rosa Junior College biology and ornithology instructor Peter Leveque.
The Vaux's Swift, which weighs about half an ounce, is the smallest of four swifts that nest in North America, Leveque said.
A relative of the hummingbird, its key features are pointed, swept back wings and weak legs, which combined with the absence of opposable toes, prevent it from perching on branches.
Instead, the bird stays on the wing all day, often flying at speeds up to 100 mph, and rests at night on the inside of hollow trees or chimneys, clinging upright in efficiently packed groups to conserve energy.
During their Wine Country stay, the birds travel as far as the Sacramento Valley in search of hunting grounds, Leveque said.
Other migratory stops include Chapman School in Portland, Ore., known to draw up to 30,000 swifts at a time, and two schools in Monroe, Wash., and nearby Selleck on Puget Sound, said Seattle resident Larry Schwitters, a retired science teacher and Audubon member. He is helping monitor the swifts, which are listed as “species of concern” by both the federal government and the state of California.
Schwitters said school chimneys are common roosts because the brick construction makes an easy hold for the birds, which have claw-like feet.
There are about 50 roosting sites from Canada down the coast to Mexico City that are being monitored in an effort to preserve aging chimneys in hopes of helping the bird survive, he said.
At Rio Lindo, the migratory population peaked in 2008 with an estimated 20,000 one night. In 2005, the largest group was only 300 strong, Benson said.
Schwitters said record counts in the Northwest so far this season suggest it could be a big year farther south, as well.
On Thursday, the birds' descent into the unused chimney at Rio Lindo Adventist took 16 minutes, entering at a rate of about 360 birds per minutes.
About 50 people were on hand to watch, many with lawn chairs, for what has become an annual rite.
“It's an amazing phenomenon,” Forestville resident Betsy Livingstone said.
“Last year I had a guy from Florida call me in the middle of summer to ask when he should come,” Benson said.
The birds arrived a week or two later than usual this year, about 400 of them roosting in the academy chimney last Sunday night. Their time at the school usually lasts two to four weeks.
In a surprise this year, a group of about 500 Vaux's Swifts also has turned up at Healdsburg Elementary School on First Street, about 1½ miles from Rio Lindo as the swift flies. They've been roosting in an unused chimney there since last Friday.
Principal Stephanie Feith said families gathered on the playground for Movie Night on Sept. 10 noticed the gathering birds overhead and watched in awe as they “started flying in a sort of a cyclone.”
Feith and Benson said the public is welcome to come observe nature's display, to come picnic or just watch. But behavior should be appropriate to campus settings: No alcohol, please.
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