This polygon shapefile depicts field observations of where each bird species nests within the nine county San Francisco Bay Area Region, California. This grid dataset displays the specific areas where breeding evidence was found. Field observation codes include: 1 for Observed, 2 for Possible, 3 for Probable and 4 for Confirmed. This data was used during the Bird Focus ProjectTeam. This dataset was developed/compiled for use in the San Francisco Bay Area Upland Habitat Goals Project, a Project used to identify a Conservation Lands Network (CLN) for biodiversity preservation to inform conservation investments and lasting cooperative conservation partnerships. The Conservation Lands Network GIS Database is the primary output of the Project. The data depicts the spatially explicit CLN that is recommended for the nine county San Francisco Bay Area Region, California. Bay Area Open Space Council, GreenInfo Network, Conservation Lands Network, and San Francisco Bay Area Upland Habitat Goals Project. (2011). Breeding Birds (Blocks): San Francisco Bay Area, California, 2002. Bay Area Open Space Council. Available at http://purl.stanford.edu/ht574ns9881. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.