Rare Bees Return to Restored Presidio Sand Dunes

Rare silver digger bees have returned to the the Presidio of San Francisco after stewardship staff and volunteers restored sand dunes in the park.

Courtesy San Francisco Chronicle / Constanza Hevia H.

April 2019 - Presidio Trust stewardship staff have discovered a sizeable colony of rare silver digger bees in newly restored Presidio sand dunes. Significant numbers of this species haven’t been spotted in San Francisco since 1928.

The sand-loving bees returned to the area after stewardship staff removed invasive ice plant, allowing the original sand dune ecosystem to flourish. Silver digger bees are one of several native species that have returned to the Presidio following restoration efforts, including rare Presidio clarkia, Western chorus frogs, coyotes, and several species of hummingbirds and butterflies.

The discovery offers some much-welcome good news, given that many bee populations are declining or disappearing due to threats like habitat loss and pesticide use. It is also another sign that removing invasives and restoring native ecosystems can be positive in unpredictable ways. With continued investment in ecological restoration projects, who knows which other lost species may return to Bay Area parklands!

An article in the San Francisco Chronicle has more, or contact Jonathan Young with any questions.

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