San Francisco baylands by Frances Freyberg

Midpen grantee SF Bay Bird Observatory publishes research in Bay Nature Magazine

Frances Freyberg


Date: March 22, 2023
Contact: Ryan McCauley, 650-772-3644,

Midpen grantee SF Bay Bird Observatory published research in Bay Nature Magazine

Los Altos, CA Research conducted by San Francisco Bay Bird Observatory (SFBBO) and Santa Clara University (SCU) and funded in part by Midpeninsula Regional Open Space District (Midpen) has been published in the Spring edition of Bay Nature Magazine by Brittney Miller. The project received nearly $25,000 during the 2018 Midpen Grantmaking Program cycle to support transitional habitat restoration.

Acting as a bridge between the tidal marsh and uplands of the San Francisco Bay estuary, transitional habitat serves as natural territory and provides cover from predators for many threatened and endangered animals that inhabit the Bay. Since most transitional habitat was lost to development and major landscape changes by the early 1900s, the plant species that used to make up this habitat are largely unknown, presenting a major roadblock to restoration work.

Together, SFBBO and SCU developed a new strategy to fill this gap in knowledge – analyzing the DNA of plants from preserved bird nests that were collected from historical transitional habitats to identify what plant species may have once grown in these environments.

An initial study published in 2021 tested whether this nest sampling strategy would work. Researchers sampled four nests from Song Sparrows and Savannah Sparrows stored in natural history collections, two of which were over 100 years old. They were able to successfully identify six plant species, including two native plants - Small Fescue (Festuca microstachys) and California Wild Rose (Rosa californica) - neither of which could be visually identified from the nest fragments alone. Small Fescue had recently been reintroduced by SFBBO at a restoration site where one of the nests was collected in 2018, suggesting these sparrows were using the native plants from the restoration when building their nests in transitional habitat – a sign of success at restoring the ecological connections in this endangered habitat. Identification of California Wild Rose in a nest collected in 1915 provided historical evidence of this species once occurring in transitional habitat, bolstering the confidence of restoration practitioners in using this plant when recreating the transitional habitat around the San Francisco Bay Area.

This success prompted an even larger study of 233 plant samples taken from 20 nests – all of which are over 100 years old and built by birds that nest primarily in the transitional habitat encircling the San Francisco Bay estuary. Next Generation sequencing technology has significantly improved their ability to identify plant species from unidentifiable nest fragments. This study is ongoing.

Read the full article in Bay Nature Magazine.

About Midpen’s Grantmaking Program

From 2007 to 2017, Midpen supported academic research on Midpen lands through its Resource Management Grant Program, which awarded small grants to local researchers. In 2018, the Midpen Board of Directors approved the replacement of the prior grant program with the current Grantmaking Program to update the focus areas and increase beneficial impact by enhancing the investment made in the program.

Midpen’s Grantmaking Program supports organizations and projects that further the understanding and protection of our natural world, build capacity in the environmental field and facilitate access to the outdoors or augment interpretation and education opportunities for the public.

The Grants Program staff encourage proposals from a diverse range of applicants and seek investments that reflect a regional focus while providing opportunities for partnership with Midpen or other stakeholders.

Grants Program staff anticipate releasing a grant solicitation for the Grantmaking Program in Summer 2023. A total of $250,000 in funding will be available for awards of up to $50,000. The Midpen Board of Directors would review proposed awards in early Spring 2024.

For more information about Midpen’s Grantmaking Program please visit or reach out to with any questions. 


The Midpeninsula Regional Open Space District’s mission is to acquire and preserve a regional greenbelt of open space land of regional significance in perpetuity, protect and restore the natural environment and provide opportunities for ecologically sensitive public enjoyment and education. On the San Mateo County coast, our mission also includes preserving agricultural land of regional significance and rural character and encouraging viable agricultural use of land resources. Midpen has successfully protected more than 70,000 acres of public open space land in the Santa Cruz Mountains region since 1972. 

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