Humboldt Bay

New HSU study shows Humboldt Bay far more important to shorebirds than previously thought

Audubon California echoes the need to preserve area's critical habitat

Humboldt Bay, Calif. – On the 20th anniversary of Humboldt Bay being named one of the most important sites for shorebirds, new research shows that far more birds rely on the bay than previously thought. For conservationists, the study highlights the importance of continuing to fight to protect this special place.

Researchers from Humboldt State University over six weeks this spring counted at least 500,000 shorebirds around the bay, far exceeding previous counts of around 100,000. The study showed that Humboldt Bay is a key Western Hemispheric site for migrating Western Sandpiper, Marbled Godwit, and Long-billed Curlew.

“Our recent efforts to quantify shorebird use of Humboldt Bay emphasize the importance of this small bay along the Pacific Flyway. During spring alone, more than half a million shorebirds make use of the bay’s mudflats, marshes and eelgrass beds that teem with the food necessary to fuel their migrations north,” said Dr. Mark Colwell, the study’s lead author. “In all likelihood this number is an under-estimate of shorebird use because it doesn’t account for the wintering populations and southbound migrants.”

The study, co-authored by Elizabeth Feucht and published this month in Wader Study an international journal, was supported by Audubon California, Redwood Region Audubon, and several other collaborators.

In recent months, Audubon California and other conservation organizations have been fighting hard to protect habitat for shorebirds and waterbirds in and around Humboldt Bay, most recently convincing the California Coastal Commission to protect eelgrass beds from expanded oyster farming.

According to Khara Strum, a conservation project manager with Audubon California, this report drives home the need to protect sites like Humboldt Bay from habitat loss.

“It’s hard to overstate the importance of Humboldt Bay to birds on the move,” Strum said. “The Bay is a critical link between stopover sites to the north and those further south. It marks the northern extent of the wintering grounds for several species and hosts one of the greatest displays of shorebird diversity along the Pacific Coast.”

Coastal wetlands like Humboldt Bay’s eelgrass beds and expansive mudflats are the most important habitat in California for shorebirds and have experienced large declines due to development.

In 1998, the Western Hemisphere Shorebird Reserve Network designated Humboldt Bay at a site of international importance for shorebirds. This new study will support the first upgrading of a WHRSN site, from international to hemispheric. Other the past 20 years, WHSRN status has supported many conservation actions in the bay, including 250 acres of wetland restoration.

About Audubon California

Audubon California is building a better future for California by bringing people together to appreciate, enjoy and protect our spectacular outdoor treasures. With more than 350,000 members and supporters in California and an affiliated 48 local Audubon chapters, Audubon California is a field program of the National Audubon Society. More information is available at

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