August, 2021: Due to the public health risks of Covid-19, the preserves are closed until further notice; however, we have a range of online activities available, detailed in the calendar.

Promoting a conservation ethic in people of all ages is central to our mission. Please join us on the preserves to explore seasonal changes, take part in naturalist training or dig in with other volunteers to assist our land management team. Reservations are required for most events in order to ensure that human impact is kept in balance with land and habitat preservation goals.

Saturday, June 19, 2021

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Heron & Egret Nest Monitoring

Audubon Canyon Ranch Event Calendar

Heron & Egret Nest Monitoring

Jun 19 2021 - 8:00am
Cypress Grove Research Center

The Heron and Egret Project is part of a collaborative effort by Audubon Canyon Ranch (ACR) and the San Francisco Bay Bird Observatory (SFBBO) to monitor colonially nesting herons and egrets in the San Francisco Bay Area. Audubon Canyon Ranch coordinates monitoring of heronries in the North Bay counties (Sonoma, Napa, Marin, Solano, and parts of Contra Costa). San Francisco Bay Bird observatory coordinates monitoring of the South Bay heronries (San Francisco, San Mateo, Alameda, Contra Costa and Santa Clara counties). The information provided here is designed to support volunteers working in the North Bay counties. For more information on volunteering in the South Bay, contact SFBBO. The data collected by volunteers in all counties contribute to intensive regional monitoring of nesting distributions, nest survivorship, nest productivity, and intra-seasonal timing of nesting.

What do volunteers do?

Heron and egret observers “adopt a nesting site” and visit it six or more times during the nesting season. Volunteers record information on bird behavior and nesting success at their colony. Volunteers must be able to identify the five species monitored by the project: Great Blue Herons, Great Egrets, Snowy Egrets, Cattle Egrets, and Black-crowned Night-Herons and must record detailed data following a written protocol.

Is there training available?

As a heron and egret observer, you will be provided a detailed protocol describing how to record your observations. New volunteers are paired with experienced observers for in-the-field training. In addition, staff biologists are available to answer questions via phone and/or email, and can meet you at your site for additonal help when needed.

Do I need special equipment?

You will need binoculars and a spotting scope, which most bird enthusiasts have already. We do have a limited number of spotting scopes available to loan.


Heron and egret observers should commit to a minimum of six observation days for the nesting season (March-June), with one visit made during each Regional Observation Period. Regional Observation Periods are pre-determined three-day time windows centered on a weekend, but always include either a Monday or a Friday for those who prefer to visit on weekdays.

How can I sign up?

Sign up here, or contact the Cypress Grove Research Center by phone: 415.663.8203 x401, or email us. We look forward to hearing from you!

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Cypress Grove Research Center