Female Anna’s Hummingbird & Hatchling – by Elyse Omernick 

Marin County Breeding Bird Atlas 2 – Frequently Asked Questions

What is a breeding bird atlas?
A breeding bird atlas is essentially a stack of maps that show the geographical distribution of birds that are nesting in a given area. An atlas project sets out to gather data for such maps within a set study period. Breeding behavior and its distribution across this area can be tracked over time, related to habitat features, and quantified in various ways. A work like this is based on a body of data that is accumulated over several years of field work.

How can I donate to support the Marin County Breeding Bird Atlas?
We are so grateful for all the volunteers that make this project a success. Even with all this generous volunteer support, we also have a number of expenses that we have to fundraise to cover to ensure the success of this endeavor. To that end, we are actively seeking donations to help support the Atlas. If you are interested in contributing a tax-deductible donation – any amount helps! – Please donate by PayPal or send a check made out to the “Marin County Breeding Bird Atlas”, ℅ Daphne Hatch, 67 Pinheiro Circle, Novato CA 94945. Or please contact Daphne at if you are considering a donation through a donor-advised fund. MAS is the fiscal sponsor of MCBBA2.

Who leads this effort?
This project is overseen by a Steering Committee that includes the three-member MCBBA2 project coordination team  (listed in the Contact Us section of this webpage) and three Marin Audubon Society members (Barbara Salzman, Doug Waterman, and Martha Jarocki). The three MCBBA2 volunteer team members coordinate the project, and with the help of a part-time Project Manager from Point Blue Conservation Science, Hilary Allen. In addition, other volunteers graciously help with various roles, including Susan Kelly as our Volunteer Coordinator. A GIS specialist, Will Wiskes, assists with geospatial data and created and curates the MCBBA2 Data Explorer found HERE. We may have the need for more volunteer help (in the following categories: volunteer engagement, data management, and fundraising) – reach out if interested! We are deeply grateful to former Steering Committee member and Regional Coordinator Joan Lamphier (1942-2022), who we lost unexpectedly, for her countless contributions. We will all miss her and her wonderful spirit.

How long will this project take?
The field work will be conducted during the breeding seasons of four consecutive years: 2021-2024, with the possibility of running a fifth survey season, should there be unacceptable gaps in our data. Production of the summary Atlas will go beyond 2024.

Will you survey the county all at once?
In order to survey the county in a systematic way, a grid system has been overlaid onto topographic maps of Marin County. This grid system results in 221 cells, or ‘study blocks’, each of which will eventually be surveyed by one or more volunteers. Over four years, the goal is to achieve adequate coverage as defined ahead of time. So, the survey will not take place county-wide simultaneously; however, at any given time during the next four breeding seasons, a significant proportion of blocks will be surveyed.

Who provides these observations?
Most observations will be provided by ‘Block Leaders’; that is, skilled volunteers who take responsibility for the field work, data collection, data entry, and data proofing for their adopted block (or blocks). Those who would like to survey but cannot take on the responsibilities of a Block Leader are still welcome to add their findings as ‘Additional Observers’. Certain data from existing, specialized bird surveys conducted by field biologists will be incorporated.

May I volunteer as a Block Leader?
Skilled birders who can commit their time and energy are welcomed! The atlas project has already signed up dozens of highly skilled observers – but more are needed. If you are good birding by ear or eager to perfect this skill; if you can readily identify our county’s birds of late spring and summer; if you are a patient observer who is willing to take on the responsibilities of a volunteer including, recording your field data and entering it online, then then contact us at

What time commitment is required?
Block Leaders are asked for a minimum commitment of 16 well-distributed hours per block, across April 15 to July 15 which is the official atlas breeding season.

I see birds nesting in my backyard or on my walks. How may I report these?
Anyone can contribute data on breeding birds. While you may do so by using eBird, a citizen science database with desktop and phone applications and a great place to capture such data in general, we will not be incorporating eBird data into the Atlas (or only very minimally). For your data to contribute directly to this project, please fill out the MCBBA2 Incidental Breeding Behavior web form, which can be quickly referenced in the third gray panel titled “Submitting your Data and Observations”, to provide reports of specific observations by location, species, and date.

I am a landowner / manager, and I’m willing to have birders come and survey my property. How can I get in touch?
It is best to get in touch with Liz Lewis, one of our Project Coordinators (), who is helping coordinate some of the private land access for this project. The Breeding Bird Atlas staff and volunteers are committed to mutually beneficial collaborations with Marin’s farm and ranch owners, as well as managers of major properties.

Are there other ways to help, such as data proofing or other clerical needs?
Help like that can be used! Please contact the Project Coordinators at

My son/daughter is interested in birding. Can they participate?
How they can help with the project depends on their skills. If you’re not sure, email us at:

When during the year do surveys take place?
To try to focus on the peak breeding period, and avoid periods where there are lots of migrants or when breeding is scarce, the official Atlas field season is April 15 to July 15. The atlas staff will accept some breeding records before and after these dates, which are to be provided via the Incidental Breeding Behavior web form, which can be quickly referenced in the third gray panel titled “Submitting Your Data & Observations”.

Will the Atlas publish the location of nests?
No, exact nest locations will not be published. The published maps will relate solid breeding evidence only to the atlas study blocks, which average about 1500 acres. This project’s prime mission is bird conservation; for this reason, the protection of our species is prioritized.

Juvenile & Female Western Screech Owl – by Elyse Omernick