Say what you will about the fall time change, but it does make catching night owls a little easier. At sunset, after her day job, Julie Woodruff heads up into the hills of Pepperwood Preserve, in the Mayacamas just north of Santa Rosa, to meet a small crew of volunteers—four or five days a week, all fall long. They string up 60 feet of nearly invisible mist nets, crank up a speaker playing what sounds like a truck backing up, and wait to see what flies in. For four hours this patch of Douglas fir and hardwoods is alive with the incessant TOOT, TOOT, TOOT, TOOT of a male northern saw-whet owl (Aegolius acadicus) advertising his territory. This and Woodruff’s other permitted station, at Las Trampas Wilderness Regional Preserve in the East Bay, are the only bird-banding stations in the region focused on saw-whets. And for the past eight years it has been a passion project—largely self-funded and totally volunteer-powered.
Each palm-size owl caught is a rush, not only because it is an encounter in the dark with pure wildness. Saw-whets are one of our most mysterious local birds, because they are so secretive and so little studied, particularly in the western U.S. That means any one capture could be a thrilling new addition to the picture of how they make their way in the world. And this year, Woodruff and crew have caught owls almost every night.
Owl camp setup takes about 10 minutes at sunset. It’s mid-November, end of the field season, and the four volunteers know their business, though the nets take some finagling. They’re a little like extra-long volleyball nets, but made of gossamer mesh sized for owl heads to get stuck in. In a clearing near the nets, a camping table is unfurled where Woodruff places a logbook and the owl tackle box, for tackled owls. She sets out supplies as precisely as an O.R. nurse: bands, pliers, a ruler, a scale, an empty apple-juice can—insert owl head-first for weighing. Hot-pink baby socks, for calming “devil spawn,” as particularly unruly subjects are called. Numbered aluminum bands on a string, sizes 4 short (for saw-whets), and 5 (for screech owls), sent by the U.S. Geological Survey’s National Banding Laboratory, which administers bird banding across the country. Also, snacks. Like most field stations, this one runs on chocolate. The crew sit in camping chairs around the table, eat dinner in the dark, chat, scroll phones, and ignore the backing-up-truck noise. Cicadas and tree frogs fill out the din. “I didn’t even notice those until you said that,” says Missy Zepeda, and others agree. But when a pygmy owl and a northern saw-whet call faintly, they all hear it. Their ears are just tuned to owl frequency.
Not harming birds is the first rule of bird banding, so the crew must be vigilant, mostly for bigger owls. Barred owls in particular can learn that an audiolure could mean an easy saw-whet dinner. (Some banders prevent this by trapping it and keeping it all night in a bag.) The nets are checked once every half-hour in part to avoid this problem. No one needs to be told when it’s time to get up and check. It just happens.
It’s a bird-nerd crew. Among them is Zepeda, a recent U.C. Davis graduate, who like Woodruff works as a biologist consultant. She started in October alongside her partner Joe Sweeney, who spent the past two summers banding seabirds in Maine. They drive up a couple of nights a week, often from Davis. Lucas Corneliussen, a U.C. Berkeley undergrad, just spent a gap year banding birds in Denmark and Australia. Jeff Robinson, who is retired, has been banding raptors for 13 years and bands passerines at Coyote Creek. He sometimes bands five days a week. They’re all why Woodruff keeps coming out. “I like trying to spark a new passion in people,” she says. Bird banding is passed down the old way, as apprenticeships. Also, she just really likes catching owls.
Saw-whets are “the perfect gateway drug to conservation,” says Scott Weidensaul, who cofounded Project OwlNet, a loose network of saw-whet banding stations across the continent, many of them grassroots ones like Woodruff’s. “You take one look at those big yellow eyes and you melt. We call it getting infected with the cute virus. There’s no cure except to spend long, cold nights in the woods.”
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7:30 p.m., zero owls. 8 p.m., nada … The crew heads uphill for some consolation stargazing. Woodruff says, “If you see a shooting star, wish for an owl.” Zepeda: “Or four or five.” Three words summarize this reporter’s first long, cold night in the woods: nothing but net. But the big yellow eyes exert their pull, and a second opportunity comes a week later.
Most of the nearly half-million North American saw-whets that have been banded in the past few decades were caught back East. In Pennsylvania in the mid-1990s, saw-whets were a candidate for state protection until people started looking for them. Playing the male “hey ladies” audiolure was a game-changer. Northern saw-whets may even be the most common forest raptor in North America. Yet Weidensaul, whose three Pennsylvania stations have banded some 15,000 birds over the past 25 years, and who bought his house in part because it seemed like good saw-whet territory, has only ever seen two birds in the wild. Most detections are by sound. On the East Coast, saw-whets are funneled (by human development and geography) into narrow wildlife corridors that make the birds fairly easy to run into, if one is a mist net. About 15 percent of the birds caught at Weidensaul’s stations are already banded, indicating how saturated the corridor is with nets. It’s a whole scene. But just five of Project OwlNet’s 126 banding stations are in California, with a handful farther north. “There’s a huge data gap between east and west coast,” Woodruff says.
If the pickings are good, a female may pump out up to 13 eggs. Ladies and gents are not faithful from year to year, sometimes not even in one season. One three-timing male was recorded. (“He must have been very busy and fit,” Woodruff says.) Some females half-raise a brood, then leave the male to it and go lay a new clutch with another guy. Imagine the energy that takes. “It’s a risk,” Weidensaul says. Saw-whets aren’t that big on parenting. Young owls, which look like two puffballs glued together with googly eyes, start leaving the nest about 29 days after hatching and are independent soon thereafter.
This is the saw-whet way of life: “Live fast, breed hard, die young,” as Weidensaul puts it. Unlike spotted owls, which live 20-plus years, saw-whets usually live four or five years. “They’re a snack for many other species, and they have a lot of other stuff going against them,” Woodruff says. Booms and busts are governed by the pine nut situation in northern forests. In a good nut year, little rodents breed hard, the saw-whets follow suit, and that fall the banding stations will see surges (called “irruptions”) of hatch-year birds, almost all females, coming down from the mountains. The males are thought to stick around in their mountain breeding grounds prospecting for nesting territory. In a bad winter a lot of them may die—they are less hardy than the larger females. But if they survive until the females show up, they’re ready. Then they sit inside old flicker holes and advertise themselves at top volume.
Saw-whets fuel this fast lifestyle with a good appetite. “They’re pretty voracious little hunters,” says Woodruff, who analyzed hawked-up pellets from saw-whets near Chico as part of her master’s thesis at California State University, Chico, from 2010 to 2014. Harvest mice were top chow there, then meadow voles and deer mice. Also featured were a handful of extremely region-specific “rain beetles,” whose larvae mature for a year before emerging as mouthless beetles for two days to mate—or get eaten. Woodruff notes that meadow voles can be the same mass as saw-whets. Let us pause to consider a human eating a human-size piece of pizza.
Reporters’ second night out comes after a big storm, which Woodruff said she was hoping would “shake loose some owls.” Third net-check, 6:30 p.m. Two owls! Both banded! One screech, one saw-whet. The screech owl goes limp like it’s waiting for all this to end (this is the way of screech) and is placed into a small drawstring cloth bag sewn by Woodruff’s mother-in-law. Meanwhile, Zepeda finds the saw-whet good and tangled. This single handful of bird, which weighs less than 1/100 of an adult human, wriggles and snaps at its captors, yellow eyes burning like Blake’s Tyger. “They have a lot of attitude,” Woodruff says. “Which is good! You want them to be fit and fighting for their life—but it’s kind of at the expense of your cuticles.” They are more dangerous to voles than to people, but a person still may need help if a bird manages to latch on. Woodruff and Robinson work the bird free of the net with dextrous fingers. Then it is bagged and carried to owl camp for processing.
Given head-scratches, the saw-whet calms, despite lights and attention. It perches in Zepeda’s hand, with its oversized head and huge eyes on a brown body slightly bigger than a robin’s. It is weighed, measured, and prodded. The bird’s larger size indicates it’s a female, like nearly all captures. (Males don’t respond to male toots. And they are thought not to migrate.) A UV flashlight on the wing confirms it is a hatch-year. This owl—band 1124-69956—has lost three grams since she was caught here and banded on Oct. 30, two weeks ago: sign of a rough life? Or maybe she pooped. A parasitic fly crawls out from under her feathers. Zepeda blows gently on the back of the owl’s neck to look for pin feathers and assesses the fat pad nestled in her wishbone (2 out of 5 stars). Under this slight breeze, the bird blinks slowly with feathered eyelids. She is the 39th saw-whet catch at Pepperwood this season. Data will be sent to the state, the national banding lab, and Project OwlNet, and available for all to use. The Pepperwood station has been seeing mostly hatch-year owls, which might signify a good reproduction year.
Questions that can’t be answered include: Where did this bird come from? Where is she headed, and how far? Mist nets give you snapshots in time. A recapture, though, is a powerful jolt of new information, showing a bird’s trajectory through time and space. Two points make a line. In her graduate fieldwork, Woodruff caught a bird in Chico that had been banded 600 miles away in Montana a month earlier. One bird banded in Chico showed up five days later at Pepperwood, 100 miles away. But such jolts are rare. The saw-whet in Zepeda’s hand is only the fourth recapture there this season, and both Bay Area stations have seen just one recapture from another site in eight years. (Three owls banded at Woodruff’s stations have turned up at other stations, all in 2022.) The stations aren’t catching a ton of owls; the most was 19, in 2023, and last year they caught only eight. In comparison, a station in British Columbia, along a narrow flyway between mountains and ocean, caught nearly 800 this fall.
But after eight years of dark nights in the woods, Woodruff at last has enough data to start digging into Bay Area trends. Unusually for migrations, the birds may be arriving in two peaks—a first flush in mid-October and a second in November. Maybe they are different age classes, with hatch-years arriving before older birds. Slowly she is teasing out their story.
“There just needs to be more work upstream of Julie,” says Weidensaul—meaning upstream in the migration paths. Tagging would also help fill out the story, bird by bird. Pepperwood is fundraising for a Motus station, a new technology using radar to sense tiny, cheap tags that is revolutionizing wildlife tracking. Woodruff hopes to do nest box studies. All the hatchlings could be tagged, overcoming banding stations’ gender gap. Then she could find out what the males are up to. But for now, banding is what is doable. “Unless you’re out there at night playing that lure and setting nets, you have no idea what’s passing through the night sky,” Weidensaul says. “Which I find really cool. There’s still so much we don’t know.”
It’s time to release the saw-whet. Sweeney takes her a few steps outside the bright circle of owl camp and stretches out his arm. Now headlamps are set to red light, to help the owl’s eyes acclimate to the night. He encourages her quietly. She blinks. She is calm. She does not leave. The headlamps are doused, and still she sits, eyes gleaming, under the stars.
At last she bursts up. Sweeney shines a light up into the trees. The owl perches on a branch—does this count as officially seeing a saw-whet in the wild?—and then she is gone. This fall Sweeney has been applying to grad schools, so he can keep studying the saw-whets with Woodruff. The cute virus is doing its work.
