San Francisco Bay NWR Complex

Join us on May 9th for Stewardship Saturday at Don Edwards San Francisco Bay National Wildlife Refuge!

Stewardship Saturday at the Don Edwards San Francisco Bay NWR in Fremont Join us for a fun volunteering day helping out in enhancing native plant communities and enjoying nature at your local bay refuge!

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We’re out at the Warm Springs Unit checking in on one of our most secretive inhabitants: the California tiger salamander! These underground specialists rely on seasonal ponds and vernal pools to breed, making their presence a sign of a thriving ecosystem. Proud to celebrate these remarkable amphibians and the habitats that support them!

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Happy birthday to the National Wildlife Refuge System.

Back in 1903, President Theodore Roosevelt set aside a small island in Florida called Pelican Island to protect nesting birds. That one decision kicked off what would become a nationwide network of protected lands dedicated to wildlife.

Today, the Refuge System includes more than 570 national wildlife refuges across the United States. These places protect critical habitat for birds, fish, mammals, reptiles, amphibians and plants, while also giving people a chance to connect with the outdoors.

Check out these numbers. National wildlife refuges receive:

🦌2.63 million annual hunting visits
🐟8.61 million annual fishing visits
🚶‍➡️4,197 miles of public trails and boardwalks, water and snow included
🚗7,352 lane miles of public roads

From quiet marshes and coastal estuaries to sweeping prairies and desert landscapes, these lands were set aside for wildlife, but they also welcome people who want to recreate, hunt, fish, photograph wildlife, and explore.

Happy birthday to the refuges.

Photo of an American avocet and chick at Don Edwards San Francisco Bay Wildlife Refuge National by Jean Zuo (sharetheexperience)

We’re very excited to report that our Habitats Team has concluded its initial planting of 2 miles of new levee at Don Edwards NWR in Alviso! This was a huge undertaking involving years of construction, growing over 35,000 plants, seeding and planting.

We’re grateful for the generous funding from California State Coastal Conservancy, for our project partners U.S. Fish and Wildlife Service, Valley Water, and H. T. Harvey & Associates, and for help from San Jose Conservation Corps + Charter School.

To read about this amazing project, view more photos, and learn how to visit, check out Science Director Eric Lynch’s blog article in our wingbeat blog (link in comments).

Alright, everybody stay calm, THISTLE only take a moment!

Volunteers at Don Edwards San Francisco Bay NWR worked hard to remove Italian thistle (Carduus pycnocephalus) to improve grassland habitats!

These prickly invaders thrive in disturbed areas and can grow over 2 yards tall. In grasslands, they often cluster around burrows dug by ground squirrels. These burrows provide essential shelter for species like the California tiger salamander, burrowing owl, and other wildlife.

When thistles block burrow entrances, they reduce habitat availability for these ground dwellers. By removing them, volunteers help restore balance and keep this ecosystem healthy.
Thank you to everyone who joined the fight against invasive species!

Not only is it , it's also ! The Farallon Islands National Wildlife Refuge hosts several species of non-native, invasive plant species.

Invasive plants such as New Zealand spinach (Tetragonia tetragonioides) outcompete native plants and degrade seabird nesting habitat. The Refuge works with teams of volunteers, known as Team Spinach, to control invasive plants to benefit native species. Thanks to all staff and volunteers who work hard to help stop the spread of New Zealand spinach! National Invasive Species Awareness Week

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For San Pablo Bay, the most concerning new potential invasive species is the nutria (Myocastor coypus). Native to subtropical and temperate regions in South America, nutria have most recently appeared and spread in California in 2017.

In January of 2026, the California Department of Fish and Wildlife reported a nutria on State Route 37, adjacent to the Refuge. We are on high alert and are working with the CDFW Nutria Eradication Project to survey for, and potentially trap, nutria on the Refuge.

Invasive nutria severely degrade brackish marsh habitat causing a threat to Threatened and Endangered species, and biodiversity to the systems they invade.

https://www.fws.gov/species/nutria-myocastor-coypus
USFWS Photo

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Invasive plants like five-hook Bassia (Bassia hyssopifolia) threaten the fragile vernal pool habitats at Don Edwards San Francisco Bay NWR, displacing native plants and endangering species such as the vernal pool tadpole shrimp and California tiger salamander.

Controlling this invader isn’t easy. It requires an integrated pest management approach that employs various methods including manual removal. Volunteer efforts, like those pictured here, are a vital part of restoring balance and protecting biodiversity.

Invasive species can transform entire ecosystems. Awareness and action matter. Thank you to everyone helping us fight the spread! National Invasive Species Awareness Week

USFWS photo: Aidona Kakouros

Moo-ving Out the Invasives!

California grasslands face a major challenge: nonnative annual grasses and invasive forbs like black mustard (Brassica nigra). These species alter hydrology and nutrient cycles, suppress native plant germination, reduce pollinator diversity, and degrade habitat quality for native wildlife. In vernal pool grasslands, the impact is even greater: they compete directly with rare and endangered species.

So, what’s the solution? Hooves to the rescue!
At the Warm Springs Unit of Don Edwards San Francisco Bay NWR, we use a targeted rotational cattle grazing program to restore balance. Long-term monitoring shows a carefully managed grazing program benefits endangered plants like Contra Costa goldfields (Lastenia conjugens) and other native species.

And here’s the best part: cattle can be trained to eat palatable invasive weeds such as mustard! A true win-win for conservation and ecosystem health! National Invasive Species Awareness Week