Since 2000, Julian Wood has perfected the art of not falling into the hidden channels that weave through the Bay’s tidal marshes. Come early spring tides, the San Francisco Bay program leader at the nonprofit Point Blue Conservation Science has his routine down: downing cups of coffee, donning rubber boots, and wayfinding out to a specific point in the marsh. Then he sets a timer for five minutes, and counts every single bird he sees or hears, from a song sparrow’s cheep to the shadow of a disappearing black rail. After five minutes, he hustles to the next spot, and repeats.
Multiply that by 12 counts a morning, several days a year, over more than two decades, and Wood has gathered a wealth of data on what birds are doing by the Bay. So have researchers from state agencies, federal agencies, and nonprofits, who have all spent years documenting birds at the Bay’s water-land interface, in four key habitats—Wood’s obstacle course, the tidal marshes; the mudflats, where shorebirds feed; open bay waters with diving ducks; and diked baylands, visited by dabbling ducks and other species.
Now they have put it all together into one report: the 2025 San Francisco Bay State of the Birds, published online last month by Point Blue Conservation Science and the San Francisco Bay Joint Venture, a partnership that helps safeguard migratory birds. The research shows a mixed bag: some bird groups, like in tidal marshes, are
The results are presented as a website, illustrated with interactive paintings of the birds in their habitat. The report’s authors suggest ways to help birds, like keeping an eye on invasive species, improving sea level rise models, and keeping gull populations down so baby avocets don’t get snatched. While it’s been a long fourteen years since the first State of the Birds in 2011, from now on the authors intend to update the website every three to five years. “It’s going to be this continuous source of data for us as we’re doing our own work,” says Casey Skinner, Audubon California’s San Francisco Bay program director, who was not involved with the report. “Reports like this can pinpoint habitats that need the most help right away.”
The results are years in the making. The 2011 SF Bay State of the Birds showed most bird populations were stable, surveying species across seven kinds of habitat. After that report, Point Blue, SF Bay Joint Venture, and other partners focused their efforts more narrowly (for funding and bandwidth reasons) on species whose population trends might reflect the health of key tidal habitats.
The story is a pretty clear win for marsh birds—species like song sparrows, whose endemic Bay subspecies depend on healthy tidal marsh plants like pickleweed. They have, on average, increased in numbers across the Bay since 1996. “My main takeaway is that restoration works,” said Wood, when presenting the report at the State of the Estuary conference in October. Some 17,202 acres of tidal marsh have been restored since 1996. “If we put the energy into the ground, actions that are guided by science, we can show those results.”
Meanwhile, shorebirds on Bay mudflats aren’t doing well—population drops range from 26 percent for small North Bay sandpipers to up to 87 percent for larger dowitchers and plovers in the central Bay. Wood remembers taking four hours, in 2006, to count enormous flocks of migrating dunlins, whimbrels, and other birds. These days it takes half as long. This decline reflects falling bird numbers across the Pacific Flyway, says Matt Reiter, a research director at Point Blue who has led these surveys since 2009. “Something bad is happening with shorebirds,” Reiter says. “Now we really need to understand why.” Reiter has ideas: maybe in some places river banks are now so protected, less sediment is getting dumped in the Bay, and tidal flats are shrinking as a result. Or maybe elsewhere on their migration, birds can’t get enough food.
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In other Bay habitats, there is no clear trend. Diving ducks, which use the open bay to rest and feed on their migrations, have decreased in the North Bay and Central Bay and increased recently in the South Bay. Scoters and scaups have declined, whereas ruddy ducks have increased. Yet more dabbling ducks are overwintering in salt ponds and diked wetlands than in the last 30 years—but the increase is mostly all northern shovelers and American wigeons. Northern pintails and mallard populations haven’t changed.
The existence of this report is a success story alone. Long-term monitoring programs almost always struggle for funding and have been particularly hard hit during the Trump administration, as Bay Nature has reported. USGS researchers furloughed during the government shutdown couldn’t finalize their sections, on subtidal and non-tidal birds, in time for the report’s launch. The tidal marsh surveys have continued since 2000, mostly, because one private individual supports them every year. But for now it lives—so next spring, Wood expects to head out again to the tidal marsh—caffeinated, booted, stopwatch at the ready.
