By Ilana DeBare
It’s the time of year when some old, out-of-use chimneys at a San Rafael brickyard become a site of avian wonder.
Tens of thousands of Vaux’s Swifts migrate south through California each fall, stopping to sleep overnight in brick chimneys, a modern version of their traditional hollow-tree roost. There are only a couple of places where the swifts are known to stop, and these sites draw up to thousands — sometimes as many as 19,000 — birds on a single night.
One of their roosting sites is the McNear Brickyard in San Rafael, discovered in 2010 by Golden Gate Audubon field trip leader and birding instructor Rusty Scalf.
Rusty continues to visit the brickyards several times each week, counting the number of swifts for a citizen-science tracking effort led by Washington state biologist Larry Schwitters.
This year’s numbers in San Rafael have been generally lower than last year. Since this year’s initial sighting on September 18, they’ve ranged from 855 to 4,000. Last fall, by comparison, the low was about 3,500 and the high was over 19,000.
I went out with Rusty on Wednesday and we counted just over 1,200. That sounds meager in comparison to last year, but it was still an amazing sight.
We waited. And waited. Saw some quail, bluebirds, House Finches, but no swifts. We waited some more, almost ready to give up. Were the swifts done with their migration already?
And then at 6:27 p.m. we saw a few, swooping near the chimney top. And then some more. And then suddenly it was a swarm, a blanket of black dots, looping and twirling in the wind.
The swifts flirt with the chimney. They circle broadly around it, as if toying with the idea of entering, and then swirl away out of sight with a gust of wind. They return and circle, and again swirl away. They could be a blizzard of dark snowflakes. They are like dancers doing some wild, fluid choreography in the wind. They are like children having too much fun to go to bed.
Finally some start popping into the chimney — one, two, ten, twenty, fifty. Hundreds continue swirling around, dozens are entering. Rusty usually brings a clicker to count them, but on Wednesday we didn’t have one so he called them out by tens and I made frantic marks on a pad.
We ended up with a count of about 1,200. On Tuesday October 1st, Emilie Strauss counted 3,440. On Thursday night, Bob Hinz counted 2,240. Why do the numbers seem lower this year? Rusty speculates that it could be the drought — fewer insects around, so maybe the birds are plowing on south without stopping.
But then there are reports from Larry Schwitters that huge numbers of swifts remain in the Northwest. One Washington chimney hosted a record 22,000 this week, a time when they usually have hundreds. So maybe the bulk of the migration hasn’t happened yet.
There’s still time for you to head over to Marin and watch!
Some data from this season:
9/18/13 – 3362 9/21/13 – 2970 9/23/13 – 2570 9/25/13 – 4000 9/26/13 – 2650 9/27/13 – 1600 9/28/13 – 2250 9/29/13 – 855 10/1/13 – 3340 10/2/13 – 1220 10/3/13 – 2240——————————————-
Want to view the Vaux’s Swifts? Arrive before 6 p.m. The brickyard is 4 miles along Point San Pedro Rd., north of the Central San Rafael exit off of Hwy 101. On Mapquest or Google Maps, you can use the address of 1 McNear Brickyard Rd., San Rafael, CA 94901. If you are willing to count, please do so and email your results to Rusty at rscalf@sonic.net.
To avoid disrupting brickyard operations, please park on San Pedro Road or the dirt shoulder just off of San Pedro Road, NOT inside the brickyard. When you walk into the brickyard, do not go further than the display of sample brick paving stones to the left of the road. The area around the paving stone display is a fine vantage point for viewing and counting. Please keep in mind that we are guests on private property and should behave accordingly.
Of course, like everything else in birding, there is no guarantee that the swifts will be there. To learn more, including how Rusty discovered the McNear roost site, read last year’s blog post. Or see http://www.vauxhappening.org for an overview of Vaux’s Swifts and their roost sites. You can also view a video of Vaux’s Swifts arriving at a chimney in Los Angeles in 2012 at
http://chanfles.com/blog/?p=